Development of optical and electrochemical sensor for environmental pollutants

Abstract

Carbon nanocomposites have garnered much attention among various nanomaterials newlineowing to their well-defined characteristics, such as large surface area, biocompatibility, newlineand concise synthetic routes. They are also a viable contender for fluorescence and newlineelectrochemical applications, notably sensing, due to their intriguing photoluminescence and electrochemical features. Fluorescence and Electrochemical sensors for environmental pollutants are constructed using carbon quantum dots with different surface functionalization (functionalized with boric acid, organic dyes, polymer composite, and 2-aminothiazole). The developed sensor was considered as potential material for detecting heavy metal ions and organic pollutants. Surface morphology was analyzed using Transmission electron microscopy (TEM), an X-ray diffraction pattern (XRD), Raman spectra, X-Ray Photoelectron spectroscopy newline(XPS), Optical Profilometry, and Fourier Transform Infrared Spectroscopy (FTIR) newlinestudies. UV-Visible and photoluminescence spectroscopy reveals the absorption, newlineemission, and excitation spectra for the synthesized sensor with and without the addition of analytes. In electrochemical investigations, Nyquist plots showed that the modified working electrodes had the lowest charge transfer resistance when compared to other working electrodes. The effect of pH, ionic strength, long-term storage ability, and quantum yield were optimized for the fabricated fluorescence sensor. For the newlineelectrochemical sensor, the influence of the scan rate and the appropriate thickness of newlinethe electrodeposited film was carefully examined in order to achieve the highest current responsiveness and potential window. Quantification of the analytes was performed newlineusing Forster resonance energy transfer (FRET), Differential Pulse Voltammetry (DPV), newlineand the square wave voltammetry technique (SWV). The designed sensor was used to newlinecarry out analytical corroboration for the real samples.