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 β-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 μM and LOD of 0.0062 µM. In addition to the DPV mode, the electrochemical sensor had a linearity of 5–450 µM with a LOD of 3.17 µM. The developed sensor exhibited remarkable analytical performances concerning high sensitivity, electrocatalytic activity, low detection limit, wide linearity, appreciable specificity, repeatability, stability, reproducibility, and adequate recovery results in food, environmental and biological samples.