Nitrogen doped graphene quantum dots modified a crystalline zinc phosphite based non-enzymatic electrochemical sensor for the ultra-low detection of tyramine

Abstract

We present the design and fabrication of a non-enzymatic sensor utilizing crystalline zinc phosphite (denoted as NT) coupled with nitrogen-doped graphene quantum dots (N-GQDs) for the detection of tyramine (TYR). The NT@N-GQDs composites were prepared through a straightforward ultrasonication technique. The obtained hybrid material exhibited exceptional electrocatalytic properties for the oxidation of TYR, attributed to the synergistic characteristics of NT and the highly conductive N-GQDs. The NT@N-GQDs sensing platform demonstrated significant sensing capabilities, with a linear range of 0.01-0.45 mM, a limit of detection of 0.04 mu M (S/N = 3), and a sensitivity of 5.17 mu A/mM/cm2. The sensing performance of NT@N-GQDs was characterized by high stability, selectivity, and reproducibility. In addition, we also examined the practical application of the NT@N-GQDs sensor by measuring TYR in samples of beer, cheese, and fish.