Layered double hydroxide decorated with Ag nanodendrites as an enhanced sensing platform for voltammetric determination of pyrazinamide

Abstract

Herein, a sensitive electrochemical sensor for pyrazinamide (PZA) based on the electrodeposition of Ag nanodendrites (AgNDs) on a Zn–Al layered double hydroxide (LDH)-modified electrode was developed. The synthesized nanostructured materials were characterized by X-ray diffraction, Fourier transform IR spectroscopy, scanning electron microscopy, and energy dispersive X-ray analysis. In addition, voltammetric measurement of double layer capacitance was used to evaluate the real surface area of the AgND/LDH/GC electrode. Excellent electrocatalytic activity, high stability, anti-interference ability, and good reproducibility make this sensor a good candidate for trace PZA determination. Under optimal experimental conditions, the current response of the fabricated sensor obtained via differential pulse voltammetry increased linearly with PZA concentrations in the wide range from 9.0 × 10⁻⁷ to 5.2 × 10⁻⁴ mol L⁻¹, and the detection limit was 7.2 × 10⁻⁷ mol L⁻¹ (S/N = 3). The proposed sensor was successfully applied for the determination of PZA in commercial pharmaceutical tablets, and the obtained results were comparable to those found by the official analytical protocols. Finally, the developed method was validated by the analysis of PZA spiked human serum and urine samples, and good recoveries were obtained in the range of 97.5–105.5%.