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Dr. Francesco Galeotti
Istituto di Scienze e Tecnologie Chimiche (SCITEC), National Research Council of Italy – Milan, Italy

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0 Polymer Chemistry
0 polydopamine
0 SERS substrates
0 colloidal assembly
0 breath figure patterns

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conjugated polyelectrolytes
SERS substrates

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Paper
Published: 01 June 2021 in Dalton Transactions
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Colloidal semiconductor nanoplatelets (NPLs) are a subgroup of quantum confined materials that have recently emerged as promising active material for solution processed light-emitting diodes (LEDs) thanks to their peculiar structural and electronic properties as well as their reduced dimensionality. Nowadays the conventional structure for NPL-based LEDs makes use of the poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as hole transporting layer (HTL). This is a well-known conjugated conductive polymer because it leads to high LED’s efficiencies, though it has limited stability in air due to its intrinsic acidity and hygroscopicity. Here, we develop a nanocomposite aqueous ink, obtained by blending commercial PEDOT:PSS with water-based, stable and highly concentrated molybdenum disulfide (MoS2) nanosheets, obtained by Liquid Phase Exfoliation (LPE) suitable as HTL for solution processed NPLs-based LEDs. We demonstrate that the MoS2 additive effectively works as a performance booster in unpackaged devices therein prolonging the lifetime up to 1000 hours upon exposure in ambient conditions. Moreover, the addition of MoS2 induces a modification of the anode interface properties, including a change in the work function and a significant enhancement of the permittivity of the HTL.

ACS Style

Roberto Sorrentino; Robyn Worsely; Paola Lagonegro; Christian Martella; Adriana Alieva; Guido Scavia; Francesco Galeotti; Mariacecilia Pasini; Benoit Dubertret; Sergio Brovelli; Alessandro Molle; Cinzia Casiraghi; Umberto Giovanella. Hybrid MoS2/PEDOT:PSS transporting layer for Interface Engineering of Nanoplatelets based Light-Emitting Diodes. Dalton Transactions 2021, 1 .

AMA Style

Roberto Sorrentino, Robyn Worsely, Paola Lagonegro, Christian Martella, Adriana Alieva, Guido Scavia, Francesco Galeotti, Mariacecilia Pasini, Benoit Dubertret, Sergio Brovelli, Alessandro Molle, Cinzia Casiraghi, Umberto Giovanella. Hybrid MoS2/PEDOT:PSS transporting layer for Interface Engineering of Nanoplatelets based Light-Emitting Diodes. Dalton Transactions. 2021; ():1.

Chicago/Turabian Style

Roberto Sorrentino; Robyn Worsely; Paola Lagonegro; Christian Martella; Adriana Alieva; Guido Scavia; Francesco Galeotti; Mariacecilia Pasini; Benoit Dubertret; Sergio Brovelli; Alessandro Molle; Cinzia Casiraghi; Umberto Giovanella. 2021. "Hybrid MoS2/PEDOT:PSS transporting layer for Interface Engineering of Nanoplatelets based Light-Emitting Diodes." Dalton Transactions , no. : 1.

Review
Published: 05 April 2021 in Applied Sciences
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The realization of advanced optical fiber probes demands the integration of materials and structures on optical fibers with micro- and nanoscale definition. Although researchers often choose complex nanofabrication tools to implement their designs, the migration from proof-of-principle devices to mass production lab-on-fiber devices requires the development of sustainable and reliable technology for cost-effective production. To make it possible, continuous efforts are devoted to applying bottom-up nanofabrication based on self-assembly to decorate the optical fiber with highly ordered photonic structures. The main challenges still pertain to “order” attainment and the limited number of implementable geometries. In this review, we try to shed light on the importance of self-assembled ordered patterns for lab-on-fiber technology. After a brief presentation of the light manipulation possibilities concerned with ordered structures, and of the new prospects offered by aperiodically ordered structures, we briefly recall how the bottom-up approach can be applied to create ordered patterns on the optical fiber. Then, we present un-attempted methodologies, which can enlarge the set of achievable structures, and can potentially improve the yielding rate in finely ordered self-assembled optical fiber probes by eliminating undesired defects and increasing the order by post-processing treatments. Finally, we discuss the available tools to quantify the degree of order in the obtained photonic structures, by suggesting the use of key performance figures of merit in order to systematically evaluate to what extent the pattern is really “ordered”. We hope such a collection of articles and discussion herein could inspire new directions and hint at best practices to fully exploit the benefits inherent to self-organization phenomena leading to ordered systems.

ACS Style

Marco Pisco; Francesco Galeotti. Nano- and Micropatterning on Optical Fibers by Bottom-Up Approach: The Importance of Being Ordered. Applied Sciences 2021, 11, 3254 .

AMA Style

Marco Pisco, Francesco Galeotti. Nano- and Micropatterning on Optical Fibers by Bottom-Up Approach: The Importance of Being Ordered. Applied Sciences. 2021; 11 (7):3254.

Chicago/Turabian Style

Marco Pisco; Francesco Galeotti. 2021. "Nano- and Micropatterning on Optical Fibers by Bottom-Up Approach: The Importance of Being Ordered." Applied Sciences 11, no. 7: 3254.

Journal article
Published: 02 February 2021 in Molecules
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Conjugated polymers with ionic pendant groups (CPEs) are receiving increasing attention as solution-processed interfacial materials for organic solar cells (OSCs). Various anionic CPEs have been successfully used, on top of ITO (Indium Tin Oxide) electrodes, as solution-processed anode interlayers (AILs) for conventional devices with direct geometry. However, the development of CPE AILs for OSC devices with inverted geometry is an important topic that still needs to be addressed. Here, we have designed three anionic CPEs bearing alkyl-potassium-sulfonate side chains. Their functional behavior as anode interlayers has been investigated in P3HT:PC61BM (poly(3-hexylthiophene): [6,6]-phenyl C61 butyric acid methyl ester) devices with an inverted geometry, using a hole collecting silver electrode evaporated on top. Our results reveal that to obtain effective anode modification, the CPEs’ conjugated backbone has to be tailored to grant self-doping and to have a good energy-level match with the photoactive layer. Furthermore, the sulfonate moieties not only ensure the solubility in polar orthogonal solvents, induce self-doping via a right choice of the conjugated backbone, but also play a role in the gaining of hole selectivity of the top silver electrode.

ACS Style

Elisa Lassi; Benedetta Squeo; Roberto Sorrentino; Guido Scavia; Simona Mrakic-Sposta; Maristella Gussoni; Barbara Vercelli; Francesco Galeotti; Mariacecilia Pasini; Silvia Luzzati. Sulfonate-Conjugated Polyelectrolytes as Anode Interfacial Layers in Inverted Organic Solar Cells. Molecules 2021, 26, 763 .

AMA Style

Elisa Lassi, Benedetta Squeo, Roberto Sorrentino, Guido Scavia, Simona Mrakic-Sposta, Maristella Gussoni, Barbara Vercelli, Francesco Galeotti, Mariacecilia Pasini, Silvia Luzzati. Sulfonate-Conjugated Polyelectrolytes as Anode Interfacial Layers in Inverted Organic Solar Cells. Molecules. 2021; 26 (3):763.

Chicago/Turabian Style

Elisa Lassi; Benedetta Squeo; Roberto Sorrentino; Guido Scavia; Simona Mrakic-Sposta; Maristella Gussoni; Barbara Vercelli; Francesco Galeotti; Mariacecilia Pasini; Silvia Luzzati. 2021. "Sulfonate-Conjugated Polyelectrolytes as Anode Interfacial Layers in Inverted Organic Solar Cells." Molecules 26, no. 3: 763.

Research article
Published: 21 April 2020 in ACS Applied Electronic Materials
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ACS Style

Paola Lagonegro; Christian Martella; Benedetta M. Squeo; Francesco Carulli; Guido Scavia; Alessio Lamperti; Francesco Galeotti; Benoit Dubertret; Mariacecilia Pasini; Sergio Brovelli; Alessandro Molle; Umberto Giovanella. Prolonged Lifetime in Nanocrystal Light-Emitting Diodes Incorporating MoS2-Based Conjugated Polyelectrolyte Interfacial Layer as an Alternative to PEDOT:PSS. ACS Applied Electronic Materials 2020, 2, 1186 -1192.

AMA Style

Paola Lagonegro, Christian Martella, Benedetta M. Squeo, Francesco Carulli, Guido Scavia, Alessio Lamperti, Francesco Galeotti, Benoit Dubertret, Mariacecilia Pasini, Sergio Brovelli, Alessandro Molle, Umberto Giovanella. Prolonged Lifetime in Nanocrystal Light-Emitting Diodes Incorporating MoS2-Based Conjugated Polyelectrolyte Interfacial Layer as an Alternative to PEDOT:PSS. ACS Applied Electronic Materials. 2020; 2 (5):1186-1192.

Chicago/Turabian Style

Paola Lagonegro; Christian Martella; Benedetta M. Squeo; Francesco Carulli; Guido Scavia; Alessio Lamperti; Francesco Galeotti; Benoit Dubertret; Mariacecilia Pasini; Sergio Brovelli; Alessandro Molle; Umberto Giovanella. 2020. "Prolonged Lifetime in Nanocrystal Light-Emitting Diodes Incorporating MoS2-Based Conjugated Polyelectrolyte Interfacial Layer as an Alternative to PEDOT:PSS." ACS Applied Electronic Materials 2, no. 5: 1186-1192.

Research article
Published: 14 April 2020 in The Journal of Physical Chemistry C
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Two terthiophene-isoindigo copolymers (P3TI-O and P3TI-D) were successfully designed and synthesized. Octyl(O) and dodecyl(D) alkyl side chains were appended at the third position of the first and fourth position of the last thiophene on the terthiophene donor units in P3TI-O and P3TI-D, respectively. The band gaps of these copolymers were less than 1.7 eV. We found intramolecular charge transfer states in both copolymers which were generated with time constants of 4.5 ps and 13 ps for the copolymers with short and long alkyl side chains on their donor units, respectively. These results indicate that an almost 3-fold faster intramolecular charge transfer process occurs when the alkyl side chain are shortened by four methyl units. Owing to a better interchain charge transfer, P3TI-O exhibits a more efficient exciton diffusion compared to P3TI-D, thus leading to longer exciton lifetimes in the copolymer with shorter alkyl side chains. Consequently, when blended with PC71BM in bulk heterojunctions, P3TI-O showed a better exciton dissociation efficiency compared to P3TI-D. These results correlate well with the higher short circuit current densities observed in P3TI-O:PC71BM inverted architecture organic solar cells compared to the P3TI-D:PC71BM ones .

ACS Style

Newayemedhin A. Tegegne; Zelalem Abdissa; Wendimagegn Mammo; Takayuki Uchiyama; Yoshiko Okada-Shudo; Francesco Galeotti; William Porzio; Mats R. Andersson; Derck Schlettwein; Varun Vohra; Heinrich Schwoerer. Effect of Alkyl Side Chain Length on Intra- and Intermolecular Interactions of Terthiophene–Isoindigo Copolymers. The Journal of Physical Chemistry C 2020, 124, 9644 -9655.

AMA Style

Newayemedhin A. Tegegne, Zelalem Abdissa, Wendimagegn Mammo, Takayuki Uchiyama, Yoshiko Okada-Shudo, Francesco Galeotti, William Porzio, Mats R. Andersson, Derck Schlettwein, Varun Vohra, Heinrich Schwoerer. Effect of Alkyl Side Chain Length on Intra- and Intermolecular Interactions of Terthiophene–Isoindigo Copolymers. The Journal of Physical Chemistry C. 2020; 124 (18):9644-9655.

Chicago/Turabian Style

Newayemedhin A. Tegegne; Zelalem Abdissa; Wendimagegn Mammo; Takayuki Uchiyama; Yoshiko Okada-Shudo; Francesco Galeotti; William Porzio; Mats R. Andersson; Derck Schlettwein; Varun Vohra; Heinrich Schwoerer. 2020. "Effect of Alkyl Side Chain Length on Intra- and Intermolecular Interactions of Terthiophene–Isoindigo Copolymers." The Journal of Physical Chemistry C 124, no. 18: 9644-9655.

Research article
Published: 09 January 2020 in ACS Applied Materials & Interfaces
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A major problem of current biomedical implants is due to bacterial colonization and subsequent biofilm formation, which seriously affects their functioning and can lead to serious post-surgical complications. Intensive efforts have been directed towards the development of novel technologies that can prevent bacterial colonization while requiring minimal antibiotics doses. To this end, biocompatible materials with intrinsic antifouling capabilities are in high demand. Silk fibroin, widely employed in biotechnology, represents an interesting candidate. Here, we employ a soft-lithography approach to realize micro- and nano-structured silk fibroin substrates, with different geometries. We show that patterned silk film substrates support mammal cells (HEK-293) adhesion and proliferation, and at the same time they intrinsically display remarkable antifouling properties. We employ Escherichia coli as representative gram-negative bacteria and we observe a up to 66% decrease in the number of bacteria that adhere to patterned silk surfaces as compared to control, flat silk samples. The mechanism leading to the inhibition of biofilm formation critically depends on the microstructures geometry, involving both a steric and a hydrophobic effect. We also couple silk fibroin patterned films to a biocompatible, optically-responsive organic semiconductor, and we verify that the antifouling properties are very well preserved. The technology described here is of interest for the next-generation of biomedical implants, involving the use of materials with enhanced antibacterial capability, easily processable, highly biocompatible and promptly available for coupling with photoimaging and photodetection techniques.

ACS Style

Gabriele Tullii; Stefano Donini; Caterina Bossio; Francesco Lodola; Mariacecilia Pasini; Emilio Parisini; Francesco Galeotti; Maria Rosa Antognazza. Micro- and Nanopatterned Silk Substrates for Antifouling Applications. ACS Applied Materials & Interfaces 2020, 12, 5437 -5446.

AMA Style

Gabriele Tullii, Stefano Donini, Caterina Bossio, Francesco Lodola, Mariacecilia Pasini, Emilio Parisini, Francesco Galeotti, Maria Rosa Antognazza. Micro- and Nanopatterned Silk Substrates for Antifouling Applications. ACS Applied Materials & Interfaces. 2020; 12 (5):5437-5446.

Chicago/Turabian Style

Gabriele Tullii; Stefano Donini; Caterina Bossio; Francesco Lodola; Mariacecilia Pasini; Emilio Parisini; Francesco Galeotti; Maria Rosa Antognazza. 2020. "Micro- and Nanopatterned Silk Substrates for Antifouling Applications." ACS Applied Materials & Interfaces 12, no. 5: 5437-5446.

Proceedings article
Published: 28 August 2019 in Seventh European Workshop on Optical Fibre Sensors
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We report on our activities related to the development of surface enhanced Raman scattering (SERS) probes realized onto the optical fiber tip (OFT) through nanosphere lithography. In the first stage of our research, we adapted the nanosphere lithography to operate on the optical fiber tip, by assessing the process and demonstrating either the potentiality or the repeatability of the proposed nanopatterning approach. Successively, we investigated the ability of the manufactured structures on the fiber tip to act as SERS probes by measuring the SERS spectra in presence of a Biphenyl Thiol (BPT) monolayer. Firstly, we focused the attention on the samples shaped as closed packed array of nanospheres covered by gold. The analysis allowed us to identify the most promising SERS platform, exhibiting an Enhancement Factor (EF) of 4×105 and a SERS measurements variability lower than 10%. We addressed also the limitations related to the use of the same optical fiber for both illumination and light collection by selecting a commercial optical fiber exhibiting a suitable trade-off in terms of high excitation/collection efficiency and low silica background. Current activities are devoted to the investigation of other nanopatterns on the optical fiber tip (namely, Sparse Array of metallodielectric spheres) and the analysis of the probes response against different molecules.

ACS Style

Giuseppe Quero; Gianluigi Zito; Stefano Managò; Francesco Galeotti; Marco Pisco; Anna Chiara De Luca; Andrea Cusano. Lab-on-fiber SERS substrates for biomolecular recognition. Seventh European Workshop on Optical Fibre Sensors 2019, 11199, 111991C .

AMA Style

Giuseppe Quero, Gianluigi Zito, Stefano Managò, Francesco Galeotti, Marco Pisco, Anna Chiara De Luca, Andrea Cusano. Lab-on-fiber SERS substrates for biomolecular recognition. Seventh European Workshop on Optical Fibre Sensors. 2019; 11199 ():111991C.

Chicago/Turabian Style

Giuseppe Quero; Gianluigi Zito; Stefano Managò; Francesco Galeotti; Marco Pisco; Anna Chiara De Luca; Andrea Cusano. 2019. "Lab-on-fiber SERS substrates for biomolecular recognition." Seventh European Workshop on Optical Fibre Sensors 11199, no. : 111991C.

Journal article
Published: 29 July 2019 in ACS Applied Materials & Interfaces
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Hybrid interfaces between living cells and nano/microstructured scaffolds have huge application potential in biotechnology, spanning from regenerative medicine and stem cell therapies to localized drug delivery and from biosensing and tissue engineering to neural computing. However, 3D architectures based on semiconducting polymers, endowed with responsivity to visible light, have never been considered. Here, we apply for the first time a push-coating technique to realize high aspect ratio polymeric pillars, based on polythiophene, showing optimal biocompatibility and allowing for the realization of soft, 3D cell cultures of both primary neurons and cell line models. HEK-293 cells cultured on top of polymer pillars display a remarkable change in the cell morphology and a sizable enhancement of the membrane capacitance due to the cell membrane thinning in correspondence to the pillars' top surface, without negatively affecting cell proliferation. Electrophysiology properties and synapse number of primary neurons are also very well preserved. In perspective, high aspect ratio semiconducting polymer pillars may find interesting applications as soft, photoactive elements for cell activity sensing and modulation.

ACS Style

Gabriele Tullii; Federica Giona; Francesco Lodola; Silvio Bonfadini; Caterina Bossio; Simone Varo; Andrea Desii; Luigino Criante; Carlo Sala; Mariacecilia Pasini; Chiara Verpelli; Francesco Galeotti; Maria Rosa Antognazza. High-Aspect-Ratio Semiconducting Polymer Pillars for 3D Cell Cultures. ACS Applied Materials & Interfaces 2019, 11, 28125 -28137.

AMA Style

Gabriele Tullii, Federica Giona, Francesco Lodola, Silvio Bonfadini, Caterina Bossio, Simone Varo, Andrea Desii, Luigino Criante, Carlo Sala, Mariacecilia Pasini, Chiara Verpelli, Francesco Galeotti, Maria Rosa Antognazza. High-Aspect-Ratio Semiconducting Polymer Pillars for 3D Cell Cultures. ACS Applied Materials & Interfaces. 2019; 11 (31):28125-28137.

Chicago/Turabian Style

Gabriele Tullii; Federica Giona; Francesco Lodola; Silvio Bonfadini; Caterina Bossio; Simone Varo; Andrea Desii; Luigino Criante; Carlo Sala; Mariacecilia Pasini; Chiara Verpelli; Francesco Galeotti; Maria Rosa Antognazza. 2019. "High-Aspect-Ratio Semiconducting Polymer Pillars for 3D Cell Cultures." ACS Applied Materials & Interfaces 11, no. 31: 28125-28137.

Journal article
Published: 02 February 2019 in Pure and Applied Chemistry
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Polar semiconducting polymers based on a conjugated polymer backbone endowed with chemically anchored polar groups on the side chains have proved to be particularly interesting as optimization layer at organic/cathode interface in optoelectronic devices. In particular, the pendant phosphonate groups impart water-alcohol solubility allowing easy solution processing, and improve electron injection thanks to both a favorable interfacial dipole of phosphonate groups and an intense coordination interaction between the phosphonate groups and Al cathode. In this work we synthesize alternating fluorene-benzothiadiazole copolymers by proposing a post-polymerization reaction to insert the phosphonate groups. Thanks to this approach it is possible to use standard Suzuki coupling conditions, simplifying the process of synthesis, purification and characterization. The polymer Poly[9,9-bis(6′-diethoxylphosphorylhexyl)-alt-benzothiadiazole] (P2), is tested in conventional organic solar cells as cathode interfacial layers showing, with respect to the control device, an increasing of all the photovoltaic parameters, with a final power conversion efficiency that reaches 5.35% starting from 4.6%. The same trend is observed for multilayered polymer light-emitting diodes with an external quantum efficiency of the P2-based PLED enhanced of 1.5 times with respect to the basic devices with bare Al cathode, and negligible roll-off efficiency. The synergic effects of energy gap modulation and of polar phosphonated pendant functionalities of P2 are compared with the corresponding fluorene-based polar homopolymer. Our results show that, not only a proper selection of side functionalities, but also the tailoring of the energy gap of cathode interfacial materials (CIMs) is a possible effective strategy to engineer cathode of different optoelectronic devices and enhance their performance.

ACS Style

Benedetta Maria Squeo; Francesco Carulli; Elisa Lassi; Francesco Galeotti; Umberto Giovanella; Silvia Luzzati; Mariacecilia Pasini. Benzothiadiazole-based conjugated polyelectrolytes for interfacial engineering in optoelectronic devices. Pure and Applied Chemistry 2019, 91, 477 -488.

AMA Style

Benedetta Maria Squeo, Francesco Carulli, Elisa Lassi, Francesco Galeotti, Umberto Giovanella, Silvia Luzzati, Mariacecilia Pasini. Benzothiadiazole-based conjugated polyelectrolytes for interfacial engineering in optoelectronic devices. Pure and Applied Chemistry. 2019; 91 (3):477-488.

Chicago/Turabian Style

Benedetta Maria Squeo; Francesco Carulli; Elisa Lassi; Francesco Galeotti; Umberto Giovanella; Silvia Luzzati; Mariacecilia Pasini. 2019. "Benzothiadiazole-based conjugated polyelectrolytes for interfacial engineering in optoelectronic devices." Pure and Applied Chemistry 91, no. 3: 477-488.

Rapid communication
Published: 04 January 2019 in ACS Medicinal Chemistry Letters
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The design and the synthesis of new self-assembling conjugates is reported. The target compounds are characterized by the presence of a self-immolative linker that secures a controlled release induced by lipase cleavage. 4-(1,2-Diphenylbut-1-en-1-yl)aniline is used as a self-assembling inducer and amino-thiocolchicine as prototype of drug. The release of thiocolchicine derivative has been demonstrated in vitro in the presence of porcine pancreatic lipase and Celite-supported lipase. The formation of nanoparticles is confirmed by dynamic light scattering, atomic force microscopy, and fluorescence microscopy. The antiproliferative activity has been proved on two human cancer cell lines.

ACS Style

Gaia Fumagalli; Laura Polito; Eleonora Colombo; Francesca Foschi; Michael S. Christodoulou; Francesco Galeotti; Dario Perdicchia; Ivan Bassanini; Sergio Riva; Pierfausto Seneci; Aída García-Argáez; Lisa Dalla Via; Daniele Passarella. Self-assembling Releasable Thiocolchicine–Diphenylbutenylaniline Conjugates. ACS Medicinal Chemistry Letters 2019, 10, 611 -614.

AMA Style

Gaia Fumagalli, Laura Polito, Eleonora Colombo, Francesca Foschi, Michael S. Christodoulou, Francesco Galeotti, Dario Perdicchia, Ivan Bassanini, Sergio Riva, Pierfausto Seneci, Aída García-Argáez, Lisa Dalla Via, Daniele Passarella. Self-assembling Releasable Thiocolchicine–Diphenylbutenylaniline Conjugates. ACS Medicinal Chemistry Letters. 2019; 10 (4):611-614.

Chicago/Turabian Style

Gaia Fumagalli; Laura Polito; Eleonora Colombo; Francesca Foschi; Michael S. Christodoulou; Francesco Galeotti; Dario Perdicchia; Ivan Bassanini; Sergio Riva; Pierfausto Seneci; Aída García-Argáez; Lisa Dalla Via; Daniele Passarella. 2019. "Self-assembling Releasable Thiocolchicine–Diphenylbutenylaniline Conjugates." ACS Medicinal Chemistry Letters 10, no. 4: 611-614.

Journal article
Published: 07 December 2018 in Journal of Colloid and Interface Science
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In this work a novel combination of side chain functionalities, alkyl-phosphonate (EP) and alkyl-ammonium bromide (NBr) groups, on a polyfluorene backbone (PF-NBr-EP) was studied as cathode interfacial material (CIM) in polymer-based solar cells. The devices were made with a conventional geometry, with PTB7:PC71 BM as active layer and aluminum as metal electrode. The CIM showed good solubility in ethanol and film forming ability onto the active layer so that its deposition could be finely tuned. The interface engineering imparted by this CIM was assessed and discussed through kelvin probe force microscopy (KPFM), impedance spectroscopy, charge recombination and electron transport characterizations. To discriminate between the interfacial modifications imparted by the interlayer and its solvent, we included in this study a surface ethanol treated device. In the optimized conditions an average power conversion efficiency of 7.24% was obtained, which is about 60% higher when compared to devices made with bare Al and 26% when compared to devices made with a standard calcium/aluminum cathode. Besides performances, some insights about the devices shelf life stability are also presented. A good persistency through aging was found for the cathode interfacial engineering capabilities of PF-NBr-EP.

ACS Style

Francesco Carulli; Guido Scavia; Elisa Lassi; Mariacecilia Pasini; Francesco Galeotti; Sergio Brovelli; Umberto Giovanella; Silvia Luzzati. A bifunctional conjugated polyelectrolyte for the interfacial engineering of polymer solar cells. Journal of Colloid and Interface Science 2018, 538, 611 -619.

AMA Style

Francesco Carulli, Guido Scavia, Elisa Lassi, Mariacecilia Pasini, Francesco Galeotti, Sergio Brovelli, Umberto Giovanella, Silvia Luzzati. A bifunctional conjugated polyelectrolyte for the interfacial engineering of polymer solar cells. Journal of Colloid and Interface Science. 2018; 538 ():611-619.

Chicago/Turabian Style

Francesco Carulli; Guido Scavia; Elisa Lassi; Mariacecilia Pasini; Francesco Galeotti; Sergio Brovelli; Umberto Giovanella; Silvia Luzzati. 2018. "A bifunctional conjugated polyelectrolyte for the interfacial engineering of polymer solar cells." Journal of Colloid and Interface Science 538, no. : 611-619.

Journals
Published: 05 November 2018 in Nanoscale
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A comprehensive review of the self-assembly techniques applied to the development of nanostructured sensing devices based on optical fibers.

ACS Style

Francesco Galeotti; Marco Pisco; Andrea Cusano. Self-assembly on optical fibers: a powerful nanofabrication tool for next generation “lab-on-fiber” optrodes. Nanoscale 2018, 10, 22673 -22700.

AMA Style

Francesco Galeotti, Marco Pisco, Andrea Cusano. Self-assembly on optical fibers: a powerful nanofabrication tool for next generation “lab-on-fiber” optrodes. Nanoscale. 2018; 10 (48):22673-22700.

Chicago/Turabian Style

Francesco Galeotti; Marco Pisco; Andrea Cusano. 2018. "Self-assembly on optical fibers: a powerful nanofabrication tool for next generation “lab-on-fiber” optrodes." Nanoscale 10, no. 48: 22673-22700.

Journal article
Published: 01 September 2018 in Surface Science
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ACS Style

E. Kozma; Francesco Galeotti; G. Grisci; L. Barba; G. Arrighetti; M. Catellani; G. Scavia; W. Porzio. Perylene diimide cysteine derivatives self-assembled onto (111) gold surface: Evidence of ordered aggregation. Surface Science 2018, 675, 15 -25.

AMA Style

E. Kozma, Francesco Galeotti, G. Grisci, L. Barba, G. Arrighetti, M. Catellani, G. Scavia, W. Porzio. Perylene diimide cysteine derivatives self-assembled onto (111) gold surface: Evidence of ordered aggregation. Surface Science. 2018; 675 ():15-25.

Chicago/Turabian Style

E. Kozma; Francesco Galeotti; G. Grisci; L. Barba; G. Arrighetti; M. Catellani; G. Scavia; W. Porzio. 2018. "Perylene diimide cysteine derivatives self-assembled onto (111) gold surface: Evidence of ordered aggregation." Surface Science 675, no. : 15-25.

Research article
Published: 09 July 2018 in ACS Applied Materials & Interfaces
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Organic light-emitting transistors (OLETs) show the fascinating combination of electrical switching characteristics and light generation capability. However, to ensure an effective device operation, efficient injection of charges into the emissive layer is required. The introduction of solution-processed conjugated polyelectrolytes (CPEs) films at the emissive layer/electrode interface represents a promising strategy to improve the electron-injection process by dipole formation. However, their use in optoelectronic devices involves also some limitations due to the ionic nature of CPEs. In this context, neutral conjugated polar polymers (CPPs) represent a valid alternative to CPEs since the conjugated backbones of CPPs are functionalized with polar non-ionic side groups, thus avoiding ion-dependent drawbacks. By introducing a layer of polyfluorene containing phosphonate groups (PF-EP) underneath the metal electrodes, we here demonstrate a substantial improvement of the electron injection properties into the OLET emissive layer and, accordingly, a more than twofold increased light power and a five-times-higher external quantum efficiency of p-type OLETs in comparison with reference devices without any interlayer. The great benefit of using a transparent glass substrate allowed to selectively investigate the morphological and photoluminescent characteristics of both CPE- and CPP-buried interlayers within complete OLETs by means of an optical scanning probe technique. This, together with a thorough optoelectronic characterization of the figures of merit of working light-emitting devices allowed to disclose the origin of the improved optical performance of CPP-based devices as well as the operation mechanisms of the investigated interlayer in the corresponding OLETs.

ACS Style

Mario Prosa; Emilia Benvenuti; Mariacecilia Pasini; Umberto Giovanella; Margherita Bolognesi; Lorenzo Meazza; Francesco Galeotti; Michele Muccini; Stefano Toffanin. Organic Light-Emitting Transistors with Simultaneous Enhancement of Optical Power and External Quantum Efficiency via Conjugated Polar Polymer Interlayers. ACS Applied Materials & Interfaces 2018, 10, 25580 -25588.

AMA Style

Mario Prosa, Emilia Benvenuti, Mariacecilia Pasini, Umberto Giovanella, Margherita Bolognesi, Lorenzo Meazza, Francesco Galeotti, Michele Muccini, Stefano Toffanin. Organic Light-Emitting Transistors with Simultaneous Enhancement of Optical Power and External Quantum Efficiency via Conjugated Polar Polymer Interlayers. ACS Applied Materials & Interfaces. 2018; 10 (30):25580-25588.

Chicago/Turabian Style

Mario Prosa; Emilia Benvenuti; Mariacecilia Pasini; Umberto Giovanella; Margherita Bolognesi; Lorenzo Meazza; Francesco Galeotti; Michele Muccini; Stefano Toffanin. 2018. "Organic Light-Emitting Transistors with Simultaneous Enhancement of Optical Power and External Quantum Efficiency via Conjugated Polar Polymer Interlayers." ACS Applied Materials & Interfaces 10, no. 30: 25580-25588.

Research article
Published: 03 May 2018 in Nano Letters
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Colloidal nanoplatelets (NPLs), owning to their efficient, narrowband luminescence, are considered promising candidates for solution-processable light-emitting diodes (LEDs) with ultra-high color purity. To date, however, the record efficiencies of NPLs-LED are significantly lower than more investigated devices based on spherical nanocrystals. This is particularly true for red-emitting NPL-LEDs, whose best reported EQE is limited to 0.63% (EQE=5% for green NPL-LEDs). Here, we address this issue by introducing a charge regulating layer of a polar/polyelectrolytic polymer specifically engineered with complementary trimethylammonium and phosphonate functionalities that provide high solubility in orthogonal polar media with respect to the NPL active layer, compatibility with the metal cathode and the ability to control electron injection through the formation of a polarized interface under bias. Through this synergic approach, we achieve EQE=5.73% at 658 nm (color saturation 98%) in fully solution-processed LEDs. Remarkably, exposure to air increases the EQE to 8.39%, exceeding the best reports of red NPL-LED by over one order of magnitude and setting a new global record for quantum dot LEDs of any color incorporating solution-deposited organic interlayers. Considering the emission quantum yield of the NPLs (40±5%), this value corresponds to a nearly unity internal quantum efficiency. Notably, our devices show exceptional operational stability for over 5 hours of continuous drive in air with no encapsulation, thus confirming the potential of NPLs for efficient, high-stability, saturated LEDs.

ACS Style

Umberto Giovanella; Mariacecilia Pasini; Monica Lorenzon; Francesco Galeotti; Claudio Lucchi; Francesco Meinardi; Silvia Luzzati; Benoit Dubertret; Sergio Brovelli. Efficient Solution-Processed Nanoplatelet-Based Light-Emitting Diodes with High Operational Stability in Air. Nano Letters 2018, 18, 3441 -3448.

AMA Style

Umberto Giovanella, Mariacecilia Pasini, Monica Lorenzon, Francesco Galeotti, Claudio Lucchi, Francesco Meinardi, Silvia Luzzati, Benoit Dubertret, Sergio Brovelli. Efficient Solution-Processed Nanoplatelet-Based Light-Emitting Diodes with High Operational Stability in Air. Nano Letters. 2018; 18 (6):3441-3448.

Chicago/Turabian Style

Umberto Giovanella; Mariacecilia Pasini; Monica Lorenzon; Francesco Galeotti; Claudio Lucchi; Francesco Meinardi; Silvia Luzzati; Benoit Dubertret; Sergio Brovelli. 2018. "Efficient Solution-Processed Nanoplatelet-Based Light-Emitting Diodes with High Operational Stability in Air." Nano Letters 18, no. 6: 3441-3448.

Original article
Published: 04 April 2018 in Chemical Papers
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Interfacial engineering provides an important tool for optimizing the performances of optoelectronic devices. We show that poly[(2,7-(9,9′-dioctyl)fluorene)-alt-(2,7-(9,9′-bis(5″-trimethylammonium bromide)pentyl)fluorene)])], an alcohol-soluble π-conjugated polymer based on polyfluorene backbone and ammonium groups on the alkyl side chains, is capable of modifying the interface between the organic layer and the metal cathode in both organic solar cells and light-emitting diodes based on commercial materials and conventional architectures, improving their performances. The introduction of the cathode interlayer enhances the efficiency of a red-emitting phosphorescent OLED by 15% and decreases its turn-on voltage. The same polymer improves the power conversion efficiency of a PTB7/PC71BM solar cell by 55% and shows a beneficial effect in terms of device stability.

ACS Style

Francesco Carulli; Wojciech Mroz; Elisa Lassi; Cristina Sandionigi; Benedetta Maria Squeo; Lorenzo Meazza; Guido Scavia; Silvia Luzzati; Mariacecilia Pasini; Umberto Giovanella; Francesco Galeotti. Effect of the introduction of an alcohol-soluble conjugated polyelectrolyte as cathode interlayer in solution-processed organic light-emitting diodes and photovoltaic devices. Chemical Papers 2018, 72, 1753 -1759.

AMA Style

Francesco Carulli, Wojciech Mroz, Elisa Lassi, Cristina Sandionigi, Benedetta Maria Squeo, Lorenzo Meazza, Guido Scavia, Silvia Luzzati, Mariacecilia Pasini, Umberto Giovanella, Francesco Galeotti. Effect of the introduction of an alcohol-soluble conjugated polyelectrolyte as cathode interlayer in solution-processed organic light-emitting diodes and photovoltaic devices. Chemical Papers. 2018; 72 (7):1753-1759.

Chicago/Turabian Style

Francesco Carulli; Wojciech Mroz; Elisa Lassi; Cristina Sandionigi; Benedetta Maria Squeo; Lorenzo Meazza; Guido Scavia; Silvia Luzzati; Mariacecilia Pasini; Umberto Giovanella; Francesco Galeotti. 2018. "Effect of the introduction of an alcohol-soluble conjugated polyelectrolyte as cathode interlayer in solution-processed organic light-emitting diodes and photovoltaic devices." Chemical Papers 72, no. 7: 1753-1759.

Research article
Published: 16 March 2018 in ACS Applied Materials & Interfaces
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Push-coating is a green and extremely low-cost process in which only few microliters of conjugated polymer solutions are used to produce thin films using capillary forces. Here, we adapt this fabrication technique to replicate self-assembled nanoporous structures on green and red light-emitting conjugated polymer thin films. These films display ring-like photoluminescence and are successfully integrated into polymer light-emitting devices as emitting layers. At low applied voltages, the green-emitting devices exhibit electroluminescence from hexagonally arranged nanopixel arrays resulting from a stronger electric field in the thinner areas inside the pores. By gradually increasing the voltage up to 10V, the emission extends to the areas around the pores. At voltages higher than 10V, a non-reversible nanopixel to nanoring-like switching of the electroluminescence can be observed. After filling the pores with a second blue-emitting conjugated polymer, voltage-dependent reversible color tuning of the electroluminescence is achieved in the nanostructured light-emitting bilayers.

ACS Style

Varun Vohra; Francesco Galeotti; Umberto Giovanella; Wojciech Mróz; Mariacecilia Pasini; Chiara Botta. Nanostructured Light-Emitting Polymer Thin Films and Devices Fabricated by the Environment-Friendly Push-Coating Technique. ACS Applied Materials & Interfaces 2018, 10, 11794 -11800.

AMA Style

Varun Vohra, Francesco Galeotti, Umberto Giovanella, Wojciech Mróz, Mariacecilia Pasini, Chiara Botta. Nanostructured Light-Emitting Polymer Thin Films and Devices Fabricated by the Environment-Friendly Push-Coating Technique. ACS Applied Materials & Interfaces. 2018; 10 (14):11794-11800.

Chicago/Turabian Style

Varun Vohra; Francesco Galeotti; Umberto Giovanella; Wojciech Mróz; Mariacecilia Pasini; Chiara Botta. 2018. "Nanostructured Light-Emitting Polymer Thin Films and Devices Fabricated by the Environment-Friendly Push-Coating Technique." ACS Applied Materials & Interfaces 10, no. 14: 11794-11800.

Journal article
Published: 25 February 2018 in Sensors
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In this paper we report on the engineering of repeatable surface enhanced Raman scattering (SERS) optical fiber sensor devices (optrodes), as realized through nanosphere lithography. The Lab-on-Fiber SERS optrode consists of polystyrene nanospheres in a close-packed arrays configuration covered by a thin film of gold on the optical fiber tip. The SERS surfaces were fabricated by using a nanosphere lithography approach that is already demonstrated as able to produce highly repeatable patterns on the fiber tip. In order to engineer and optimize the SERS probes, we first evaluated and compared the SERS performances in terms of Enhancement Factor (EF) pertaining to different patterns with different nanosphere diameters and gold thicknesses. To this aim, the EF of SERS surfaces with a pitch of 500, 750 and 1000 nm, and gold films of 20, 30 and 40 nm have been retrieved, adopting the SERS signal of a monolayer of biphenyl-4-thiol (BPT) as a reliable benchmark. The analysis allowed us to identify of the most promising SERS platform: for the samples with nanospheres diameter of 500 nm and gold thickness of 30 nm, we measured values of EF of 4 × 105, which is comparable with state-of-the-art SERS EF achievable with highly performing colloidal gold nanoparticles. The reproducibility of the SERS enhancement was thoroughly evaluated. In particular, the SERS intensity revealed intra-sample (i.e., between different spatial regions of a selected substrate) and inter-sample (i.e., between regions of different substrates) repeatability, with a relative standard deviation lower than 9 and 15%, respectively. Finally, in order to determine the most suitable optical fiber probe, in terms of excitation/collection efficiency and Raman background, we selected several commercially available optical fibers and tested them with a BPT solution used as benchmark. A fiber probe with a pure silica core of 200 µm diameter and high numerical aperture (i.e., 0.5) was found to be the most promising fiber platform, providing the best trade-off between high excitation/collection efficiency and low background. This work, thus, poses the basis for realizing reproducible and engineered Lab-on-Fiber SERS optrodes for in-situ trace detection directed toward highly advanced in vivo sensing.

ACS Style

Giuseppe Quero; Gianluigi Zito; Stefano Managò; Francesco Galeotti; Marco Pisco; Anna Chiara De Luca; Andrea Cusano. Nanosphere Lithography on Fiber: Towards Engineered Lab-On-Fiber SERS Optrodes. Sensors 2018, 18, 680 .

AMA Style

Giuseppe Quero, Gianluigi Zito, Stefano Managò, Francesco Galeotti, Marco Pisco, Anna Chiara De Luca, Andrea Cusano. Nanosphere Lithography on Fiber: Towards Engineered Lab-On-Fiber SERS Optrodes. Sensors. 2018; 18 (3):680.

Chicago/Turabian Style

Giuseppe Quero; Gianluigi Zito; Stefano Managò; Francesco Galeotti; Marco Pisco; Anna Chiara De Luca; Andrea Cusano. 2018. "Nanosphere Lithography on Fiber: Towards Engineered Lab-On-Fiber SERS Optrodes." Sensors 18, no. 3: 680.

Conference paper
Published: 01 January 2018 in 26th International Conference on Optical Fiber Sensors
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We report on the engineering of repeatable surface enhanced Raman scattering (SERS) probes realized through nanosphere lithography. The Lab-on-Fiber SERS probes consist of polystyrene nanospheres in close-packed arrays (CPA), covered by a thin film of gold, on the optical fiber tip. We systematically studied the SERS performances of the CPA samples by comparing different patterns featured by different nanosphere diameters and gold thicknesses. The analysis allowed us to identify the most promising CPA SERS platform, exhibiting an Enhancement Factor (EF) of 4 × 105 and a SERS measurements variability lower than 10%. We addressed also the limitations related to the use of the same optical fiber for both illumination and light collection by selecting a commercial optical fiber exhibiting a good trade-off in terms of high excitation/collection efficiency and low silica background. Overall, the obtained results represent a step forward towards the realization of repeatable Lab on Fiber SERS optrodes for in vivo clinical studies.

ACS Style

G. Quero; G. Zito; Stefano Managò; Francesco Galeotti; M. Pisco; A. Cutolo; A. C. De Luca; A. Cusano. Engineered Lab on Fiber SERS probes by “Self-Assembly on Fiber” technique. 26th International Conference on Optical Fiber Sensors 2018, TuE7 .

AMA Style

G. Quero, G. Zito, Stefano Managò, Francesco Galeotti, M. Pisco, A. Cutolo, A. C. De Luca, A. Cusano. Engineered Lab on Fiber SERS probes by “Self-Assembly on Fiber” technique. 26th International Conference on Optical Fiber Sensors. 2018; ():TuE7.

Chicago/Turabian Style

G. Quero; G. Zito; Stefano Managò; Francesco Galeotti; M. Pisco; A. Cutolo; A. C. De Luca; A. Cusano. 2018. "Engineered Lab on Fiber SERS probes by “Self-Assembly on Fiber” technique." 26th International Conference on Optical Fiber Sensors , no. : TuE7.

Journal article
Published: 04 December 2017 in New Journal of Chemistry
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The electronic and optical properties of fluorenyl functionalized perylene diimides are influenced by the substituent position on the perylene core.

ACS Style

Erika Kozma; Wojciech Mroz; A. Andicsová Eckstein; Vladimír Lukeš; Francesco Galeotti; Alena Šišková; Martin Danko; Marinella Catellani. A joint experimental and theoretical study on the electro-optical properties of 1,6- and 1,7-fluorenyl disubstituted perylene diimide isomers. New Journal of Chemistry 2017, 42, 1061 -1066.

AMA Style

Erika Kozma, Wojciech Mroz, A. Andicsová Eckstein, Vladimír Lukeš, Francesco Galeotti, Alena Šišková, Martin Danko, Marinella Catellani. A joint experimental and theoretical study on the electro-optical properties of 1,6- and 1,7-fluorenyl disubstituted perylene diimide isomers. New Journal of Chemistry. 2017; 42 (2):1061-1066.

Chicago/Turabian Style

Erika Kozma; Wojciech Mroz; A. Andicsová Eckstein; Vladimír Lukeš; Francesco Galeotti; Alena Šišková; Martin Danko; Marinella Catellani. 2017. "A joint experimental and theoretical study on the electro-optical properties of 1,6- and 1,7-fluorenyl disubstituted perylene diimide isomers." New Journal of Chemistry 42, no. 2: 1061-1066.