Polypropylene (PP) is a key component of nanoplastics detected globally in water, which can carry pollutants through co-transport. In this regard, the co-transport of perfluoroalkyl substances (PFAS) by nanoplastics (NPs) raises significant concern, as NPs can act as vectors that enhance PFAS uptake and bioaccumulation in organisms during co-exposure. In this context, research has shown interactions between NPs and PFAS, but the adsorption mechanism remains still unclear. In this work, a powerful synergic approach combining several computational and experimental techniques has been used to unveil the adsorption mechanism of perfluorooctanesulfonate (PFOS), which is one of the most widespread contaminants of emerging concerns (CECs) on PP nanoparticles. According to our DFT results, PFOS adsorbs onto the outer and inner surface of the nanoparticle, with a maximum adsorption energy of ≈ 18 kcal/mol and an adsorption mechanism mainly governed by dispersion forces between the two fragments. Batch experiments have confirmed that PFOS rapidly adsorbs on PP nanoparticle, showing that pH can reduce the adsorption capacity thus affecting the co-transport. Moreover, the dipole moment of the PFOS-nanoparticle complex has been found to be significantly larger as compared to the bare nanoparticle, resulting in a more pronounced transport in aqueous environment and making the PFOS-PP nanoparticle complex much more dangerous than the bare PP nanoparticle. Altogether, our results allowed us to disentangle the adsorption mechanism of PFAS on PP nanoparticles, which is a fundamental step to understand the co-occurrence of such dangerous pollutants in environmental matrices, as well as to obtain new information for toxicity and risk-models development.

Electrochemical immunosensors are affinity-based biosensors characterized by several useful features such as specificity, miniaturizability, low cost and simplicity, making them very interesting for many applications in several scientific fields. One of the significant issues in the design of electrochemical immunosensors is to increase the system’s sensitivity. Different strategies have been developed, one of the most common is the use of nanostructured materials as electrode materials, nanocarriers, electroactive or electrocatalytic nanotracers because of their abilities in signal amplification and biocompatibility. In this review, we will consider some of the most used nanostructures employed in the development of electrochemical immunosensors (e.g., metallic nanoparticles, graphene, carbon nanotubes) and many other still uncommon nanomaterials. Furthermore, their diagnostic applications in the last decade will be discussed, referring to two relevant issues of present-day: the detection of tumor markers and viruses.

A single-use electrochemical screen-printed electrode is reported based on biomimetic properties of nanoceria particles (CeNPs). The developed tool showed an easy approach compared to the classical spectrophotometric methods reported in literature in terms of ease of use, cost, portability, and unnecessary secondary reagents. The sensor allowed the detection of the total antioxidant capacity (TAC) in wine samples. The sensor has been optimized and characterized electrochemically and then tested with antioxidant compounds occurred in wine samples. The electrochemical CeNPs modified sensor has been used for detection of TAC in white and red commercial wines and the data compared to the 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS)-based spectrophotometric method. Finally, the obtained results have demonstrated that the proposed sensor was suitable for the simple and quick evaluation of TAC in beverage samples.

We report a new sensitive label-free electrochemical immunosensor to detect Vitamin D₃ (25-OHD₃) in untreated serum samples. To this aim, a graphite screen printed electrode (SPE) was modified using cysteamine (CYM) functionalized core-shell magnetic nanoparticles (Au@MNPs) then, the 25-OHD₃ antibody (AbD) was immobilized via glutaraldehyde crosslinking. The several steps involved in the immunosensor development and 25-OHD₃ analysis were monitored by using differential pulse voltammetry (DPV). The developed immunosensor showed a LOD of 2.4 ng mL^-1 and a linear range between 7.4 and 70 ng mL^-1. The effectiveness of the immunosensor in human serum analysis was assessed by comparing the results obtained with the chemiluminescence-immunoassay (CLIA) reference method. The high sensitivity and excellent agreement with the reference method suggest its potential use as a POCT to monitor hypovitaminosis 25-OHD levels.

Nanoparticle‐based electrochemical immunosensors are fascinating and promising screening systems that rely on the affinity binding between antibodies and antigens, allowing the specific detection of diverse types of targets (e. g., proteins, hormones, antibodies). The employment of nanoparticles in the realization of such devices dramatically improves the selectivity, sensitivity, and the transducer surface area for effectively immobilizing the bioreceptor or target molecules. During the last years, the nanoparticles design and fabrication was mainly focused on taking advantage from synergistic effects due to the coupling of different materials. In this review, we summarize the very recent advancements in this regard, with specific emphasis to nanoparticle syntheses procedures, antibody oriented immobilization strategies and transduction techniques. Moreover, the last trends and applications have been extensively discussed along with the remaining challenges and future perspectives.