Facile synthesis of a nanorod-like MoS2 nanostructure for sensitive electrochemical biosensing application

Abstract

A novel nanorod-like MoS₂ semiconductor nanostructure was synthesized through a simple two-step method. The nanorod-like MoS₂ nanostructure was exploited as an electrode material to immobilize enzymes and for electrochemical sensing application. Characterization of the nanorod-like MoS₂ nanostructure and the resultant biosensor was performed by scanning electron microscopy, Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, and cyclic voltammetry. Enzyme molecules loaded at the MoS₂ nanostructure retained their native structure and bioactivity. The direct electron transfer of glucose oxidase at the MoS₂ nanostructure coated glassy carbon electrode was enhanced greatly. At an optimal potential of −0.45 V, the electrochemical glucose sensor had wide linear ranges of 1.5 × 10⁻⁵–3.25 × 10⁻⁴ M and 3.25 × 10⁻⁴–1.43 × 10⁻³ M, and a low detection limit of 0.005 mM (S/N = 3) with a high sensitivity of 25.06 ± 0.5 mA M⁻¹ cm⁻². At the same time, the present biosensor showed excellent selectivity, reproducibility and stability for glucose. What's more, the biosensor was successfully applied to the determination of practical samples.