Nitrogen doped graphene nanosheet supported platinum nanoparticles as high performance electrochemical homocysteine biosensors

Functional carbon nanomaterials are significantly important for the development of high performance<br>sensitive and selective electrochemical biosensors. In this study, graphene supported platinum<br>nanoparticles (GN–PtNPs) and nitrogen doped graphene supported platinum nanoparticles (N-GN–<br>PtNPs) were synthesized by a simple chemical reduction method and explored as high performance<br>nanocatalyst supports, as well as doped nanocatalyst supports, toward electrochemical oxidation of<br>homocysteine (HCY) for the first the time. Our studies demonstrate that N-doped graphene supported<br>PtNPs show higher electrocatalytic activity for HCY with an experimental detection limit of 200 pM.<br>Moreover, N-doped graphene supported Pt was demonstrated to have excellent selectivity in the<br>electrochemical oxidation of HCY i.e., the detection of HCY is successful in the presence of a 20-fold<br>excess of ascorbic acid (AA). The practical application of N-doped graphene supported PtNP materials is<br>effectively shown for the determination of HCY in both human blood serum and urine samples, by<br>differential pulse voltammetry under optimized conditions. Our findings conclude that N-doped<br>graphene supported PtNPs can be developed as a high performance and versatile nano-electrocatalyst<br>for electrochemical biosensor applications.