ABSTRACT
There is an urgent need to develop in situ sensors that monitor the continued release of H2S from biological systems to understand H2S-related pathology and pharmacology. For this purpose, we have developed a molybdenum disulfide supported double-layered zinc cobaltite modified carbon cloth electrode (MoS2-ZnCo2O4-ZnCo2O4) based electrocatalytic sensor. The results of our study suggest that the MoS2-ZnCo2O4-ZnCo2O4 electrode has excellent electrocatalytic ability to oxidize H2S at physiological pH, in a minimized overpotential (+0.20 vs. Ag/AgCl) with an amplified current signal. MoS2 grown on double-layered ZnCo2O4 showed relatively better surface properties and electrochemical properties than MoS2 grown on single-layered ZnCo2O4. The sensor delivered excellent analytical parameters, such as low detection limit (5 nM), wide linear range (10 nM-1000 µM), appreciable stability (94.3%) and high selectivity (2.5-fold). The practicality of the method was tested in several major biological fluids. The electrode monitors the dynamics of bacterial H2S in real-time for up to 5 h with good cell viability. Our research shows that MoS2-ZnCo2O4-ZnCo2O4/carbon cloth is a robust and sensitive electrode to understand how bacteria seek to adjust their defense strategies under exogenously induced stress conditions.
