Layered double hydroxide nanoparticles embedded in a biopolymer: a novel platform for electroanalytical determination of diazepam

This paper describes the development of a sensitive and efficient sensing platform based on a layered double hydroxide/poly(tyrosine) (LDH/poly(Tyr)) film for electrochemical determination of diazepam (DZ). The morphology and chemical composition of the LDH/poly(Tyr) film was illustrated by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) techniques. The electro-polymerization parameters of poly(Tyr) were discussed in detail. It was found that the reduction peak current of DZ was enhanced significantly on the film electrode. Under optimal experimental conditions, the calibration curve was linear over the DZ concentration range 2.0 x 10(-7)-6.0 x 10(-5) mol L-1 with a detection limit (S/N = 3) of 7.8 x 10(-8) mol L-1. The novel sensor developed in this study exhibited long-term stability, anti-interference ability and good reproducibility. Finally, the application of the proposed method in the analysis of real samples (commercial tablets and plasma samples) was also evaluated with satisfactory results, demonstrating that the LDH/poly(Tyr) film is a promising platform for accurate and reproducible detection of DZ.