Electrochemically synthesized superhydrophilic 3D tree-like Ag microstructure for ultrasensitive detection of omethoate

Abstract

In this work, electrodeposition, a simple, fast and convenient method, was used to prepare a superhydrophilic 3D tree-like silver (Ag) microstructure and a acetylcholinesterase (AChE) biosensor was constructed based on 3D tree-like Ag. Several advantages were illustrated in this work as follows: the electrodeposition method provided uniform distribution and stable adhesion of the material at the electrode surface; the superhydrophilic property of the prepared material could increase the contact area between the electrode surface and the liquid (solid–liquid interphase); and the rough structure of the 3D tree-like Ag could provide a good microenvironment for the enzyme load. These features all greatly improved the sensitivity and stability of biosensors. Under the optimal conditions, the AChE/3D tree-like Ag/GCE biosensor obtained a high sensitivity of 0.056 μA mM−1, a wide linear range from 10-13 M to 10-7 M, and a low detection limit of 1.26 × 10-14 M (calculated for S/N = 3), which was much smaller than the maximum amount permitted by Chinese National Standards (20 μg/kg). The prepared biosensor also obtained excellent reproducibility and stability. Moreover, the feasibility of the prepared biosensor to detect omethoate in real samples has been confirmed with good recovery (97.2%-102.2%).