Supercapacitors are a new brand of high‐performance nanoengineered devices that match the high capacity of batteries for electric energy storage with the ability of dry capacitors for ultra‐fast charging or discharging rates. Thus, supercapacitors are capable of simultaneously providing the high energy‐density and high power‐density, demanded in a plethora of biosensors and portable electronic devices. In this review, a variety of nanomaterials investigated for possible applications in novel supercapacitors have been evaluated including different carbon nanoforms, metal oxides or hydroxides, chalcogenides, carbides and phosphates, as well as organic redox species, conductive polymers, metal‐organic frameworks, MXenes and others. Different strategies for boosting volumetric capacitance, power density and charge or discharge cycling stability of micro‐supercapacitors (MSCs) designed from these materials have been reviewed and their application potential assessed. Special attention has been given to micro‐supercapacitor's designs that are suitable for miniaturization and integration with flexible microcircuits for wearable and implantable biomedical devices, remotely rechargeable sensors, microprocessor‐controlled data processing chips, biomorphic computing, smart phone communication, military, automotive applications and emerging technologies. The different strategies applied for MSCs design and fabrication, including femto‐laser writing, photolithography, screen printing, stamping, inkjet printing, mask patterning and others, have been assessed. The exciting future perspectives of MSCs have been discussed.

The field of nanomedicine has recently emerged as a product of the expansion of a range of nanotechnologies into biomedical science, pharmacology and clinical practice. Due to the unique properties of nanoparticles and the related nanostructures, their applications to medical diagnostics, imaging, controlled drug and gene delivery, monitoring of therapeutic outcomes, and aiding in medical interventions, provide a new perspective for challenging problems in such demanding issues as those involved in the treatment of cancer or debilitating neurological diseases. In this review, we evaluate the role and contributions that the applications of magnetic nanoparticles (MNPs) have made to various aspects of nanomedicine, including the newest magnetic particle imaging (MPI) technology allowing for outstanding spatial and temporal resolution that enables targeted contrast enhancement and real-time assistance during medical interventions. We also evaluate the applications of MNPs to the development of targeted drug delivery systems with magnetic field guidance/focusing and controlled drug release that mitigate chemotherapeutic drugs’ side effects and damage to healthy cells. These systems enable tackling of multiple drug resistance which develops in cancer cells during chemotherapeutic treatment. Furthermore, the progress in development of ROS- and heat-generating magnetic nanocarriers and magneto-mechanical cancer cell destruction, induced by an external magnetic field, is also discussed. The crucial roles of MNPs in the development of biosensors and microfluidic paper array devices (µPADs) for the detection of cancer biomarkers and circulating tumor cells (CTCs) are also assessed. Future challenges concerning the role and contributions of MNPs to the progress in nanomedicine have been outlined.

The optical properties of a photoluminescent dye rhodamine B (RhB) interacting with gold nanoparticles (AuNP) have been investigated using plasmonic absorbance, fluorescence, and resonance elastic light scattering (RELS) spectroscopy. We have found that these interactions result in a multimodal coupling that influence optical transitions in RhB. In absorbance measurements, we have observed for the first time the coupling resulting in strong screening of RhB π–π* transitions, likely caused by a contact adsorption of RhB on a conductive surface of AuNP. The nanoparticles quench also very efficiently the RhB fluorescence. We have determined that the static quenching mechanism with a non-Förster fluorescence resonance energy transfer (FRET) from RhB molecules to AuNP is involved. The Stern–Volmer dependence F₀/F = f(Q) shows an upward deviation from linearity, attributed to the ultra-high quenching efficiency of AuNP leading to the new extended Stern–Volmer model. A sharp RELS peak of RhB alone (λ_max = 566 nm) has been observed for the first time and attributed to the resonance fluorescence and enhanced scattering. This peak is completely quenched in the presence of AuNP_22nm. Our quantum mechanical calculations confirm that the distance between AuNP surface and conjugated π-electron system in RhB is well within the range of plasmonic fields extending from AuNP. The optical transition coupling to plasmonic oscillations and the efficient energy transfer due to the interactions of fluorescent dyes with nanoparticles are important for biophysical studies of life processes and applications in nanomedicine.