▎ 摘　　要

The rapid quantification of drugs in biological samples has become an important issue and ongoing challenge to protect human health. To address this issue, we designed and synthesized a tin phosphate-entrapped graphene flake (SnP/GRF) nanocomposite for the trace level electrochemical detection of the antituberculosis drug isoniazid (ISZ). Moreover, the successful formation of the SnP/GRF nanocomposite was confirmed by various spectroscopic and analytical techniques. Based on its synergistic effect, the proposed electrode material exhibits excellent and superior electrochemical activity towards ISZ detection. The SnP/GRF nanocomposite-modified electrode possesses high electric conductivity and good charge transfer, which is highly desired for an advanced electrocatalyst. Benefiting from the fabricated SnP/GRF-modified electrode, the ISZ sensing exhibited a wide dynamic working range (0.01 to 348 mu M) and a low detection limit (1.0 nM) with outstanding sensitivity (1.418 mu A mu M-1 cm(-2)). More importantly, the SnP/GRF-based electrochemical sensing system also has good storage stability, reliable reproducibility, rapid response time and high selectivity. Our proposed electrochemical sensor has promising potential for the determination of ISZ in biological samples. Our work represents an innovative design to fabricate multifunctional catalysts for versatile applications in emerging next-generation electrochemical fields.