Highly responsive and sensitive non-enzymatic electrochemical sensor for the detection of β-NADH in food, environmental and biological samples using AuNP on polydopamine/titanium carbide composite

In this study, a polydopamine/titanium carbide adorned with gold nanoparticles (Au@PDA/TiC) composite was prepared by a simple stirring technique and it was used for the dual-technique detection of beta-Nicotinamide adenine dinucleotide (NADH). The Au@PDA/TiC-modified glassy carbon electrode (GCE) oxidized NADH at a very low oxidation potential of approximately 0.60 V vs Ag/AgCl in pH = 7.0 (0.1 M PBS) via the transfer of two electrons and one proton (from NADH to NAD(+)). Based on the (i-t) amperometry mode, NADH can be quantified with a linear range of 0.018-674 mu M and LOD of 0.0062 mu M. In addition to the DPV mode, the electrochemical sensor had a linearity of 5-450 mu M with a LOD of 3.17 mu M. The developed sensor exhibited remarkable analytical performances concerning high sensitivity, electrocatalytic activity, low detection limit, wide linearity, appre-ciable specificity, repeatability, stability, reproducibility, and adequate recovery results in food, environmental and biological samples.