CuO nanoflakes anchored polythiophene nanocomposite: Voltammetric detection of L-Tryptophan

Abstract

This research paper describes the detailed study of selective electrochemical determination of L-Tryptophan (L-Try) based on electrostatically interacted copper oxide (CuO) nanoflakes with polythiophene (PT). The purity and geometrical structure of PT-CuO nanocomposite was certified using different characterization techniques, including X-ray diffraction (XRD), UV–Vis spectroscopy, RAMAN spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). L-Try is a naturally occurring amphipathic and essential amino acid serving for various purposes like nitrogen balance and neurotransmitter. Also, L-Try is having complex chemical characteristics and side chain dipoles which could be noteworthy for functionalization. The sulfur groups of PT interact effectively with free α-amine group and α-carboxylic acid group of L-Try, which results in increased conductance of the PT-CuO modified glassy carbon electrode (GCE). Under optimized conditions, the peak current of L-Try is increased linearly with concentration range of 100 nM to 1 mM and its limit of detection is 15 nM with 3515.62 µA M−1 cm−2 sensitivity. It is observed that, the PT-CuO modified GCE exhibited admirable electro-catalytic activities, reproducibility, rapid response and high selectivity towards the oxidation of L-Try. Also, the PT-CuO modified GCE is used to determine L-Try concentration in real sample like milk with satisfactory results.