Optical Chemosensors for Cations Based on 1,8-Naphthalimide Derivatives

This review presents the examples of fluorescent sensors for metal cations based on a 1,8-naphthalimide optical platform and covers the main advances in this field for the last decade. The mechanisms of the generation of an optical signal are discussed in detail. Special attention is given to the authors' own works.

Give or Take: Effects of Electron-Accepting/-Withdrawing Groups in Red-Fluorescent BODIPY Molecular Rotors

Mapping microviscosity, temperature, and polarity in biosystems is an important capability that can aid in disease detection. This can be achieved using fluorescent sensors based on a green-emitting BODIPY group. However, red fluorescent sensors are desired for convenient imaging of biological samples. It is known that phenyl substituents in the β position of the BODIPY core can shift the fluorescence spectra to longer wavelengths. In this research, we report how electron-withdrawing (EWG) and -donating (EDG) groups can change the spectral and sensory properties of β-phenyl-substituted BODIPYs. We present a trifluoromethyl-substituted (EWG) conjugate with moderate temperature sensing properties and a methoxy-substituted (EDG) molecule that could be used as a lifetime-based polarity probe. In this study, we utilise experimental results of steady-state and time-resolved fluorescence, as well as quantum chemical calculations using density functional theory (DFT). We also explain how the energy barrier height (Ea) for non-radiative relaxation affects the probe’s sensitivity to temperature and viscosity and provide appropriate Ea ranges for the best possible sensitivity to viscosity and temperature.

Fluorescent Biosensors Based on Silicon Nanowires

Nanostructures are arising as novel biosensing platforms promising to surpass current performance in terms of sensitivity, selectivity, and affordability of standard approaches. However, for several nanosensors, the material and synthesis used make the industrial transfer of such technologies complex. Silicon nanowires (NWs) are compatible with Si-based flat architecture fabrication and arise as a hopeful solution to couple their interesting physical properties and surface-to-volume ratio to an easy commercial transfer. Among all the transduction methods, fluorescent probes and sensors emerge as some of the most used approaches thanks to their easy data interpretation, measure affordability, and real-time in situ analysis. In fluorescent sensors, Si NWs are employed as substrate and coupled with several fluorophores, NWs can be used as quenchers in stem-loop configuration, and have recently been used for direct fluorescent sensing. In this review, an overview on fluorescent sensors based on Si NWs is presented, analyzing the literature of the field and highlighting the advantages and drawbacks for each strategy.

Semiconductor gas sensors detecting hydrogen peroxide

The results of studies of many types of semiconductor H2 O2 sensors are discussed in this review of 185 articles about hydrogen peroxide. The properties of electrochemical detectors, sensors based on organic and inorganic materials, graphene, and nano-sensors are analyzed. Optical and fluorescent sensors, detectors made of porous materials, quantum dots, fibers, and spheres are briefly discussed. The results of our studies in the YSU of hydrogen peroxide sensors made from solid solutions of carbon nanotubes with semiconducting metal oxides are also presented in the review. The fundamentals of the manufacture of biomarkers of respiration containing hydrogen peroxide vapors, which make it possible to judge the degree of a person's illness with various respiratory diseases (asthma, lung cancer, etc.), are discussed.