Trimethylamine N-oxide detection by electrochemical sensor based on screen printed electrode modified with molecularly imprinted polypyrrole-molybdenum(III) sulfide nanosheets

Trimethylamine N-oxide (TMAO) is a gut metabolite produced by dietary L-carnitine and choline metabolism. Its altered level in the serum has been implicated in human health and diseases such as colorectal Cancer, chronic kidney diseases, cardiovascular diseases, etc. Early detection of TMAO in body fluids has been presumed to be significant in understanding the pathogenesis and treatment of many diseases. Hence, developing reliable and rapid technologies for its detection may augment our understanding of pathogenesis and diagnosis of diseases. Hence, in the present work, polypyrrole (Ppy)@molybdenum(III)sulfide (Mo₂S₃) nanosheets (NS) composite molecularly imprinted polymer (MIP) (Ppy@Mo₂S₃-MIP) based electrochemical sensor has been fabricated for the detection of TMAO. Polypyrrole (Ppy) and Mo₂S₃ NS have been synthesized by chemical oxidative polymerization and hydrothermal techniques, respectively. The synthesized nanocomposite has been validated using different techniques such as X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The fabricated Ppy@Mo₂S₃-MIP sensor showed a linear detection range from 30 µM to 210 µM, a sensitivity of 1.21 μA μM^-1 cm^-2 and a limit of detection as 1.4 μM for the detection of TMAO and found more robust and improved when compared with Ppy-MIP using identical parameters. The fabricated sensor is also highly selective towards TMAO. It can be further used to detect TMAO in human samples such as urine quickly.

Electrochemical sensor; Gut microbiota derived metabolites; Molecularly imprinted polymer; TMAO; Voltammetry.