Synthesis of reticulated hollow spheres structure NiCo2S4 and its application in organophosphate pesticides biosensor.

Electrode materials play a key role in the development of electrochemical sensors, particularly enzyme-based biosensors. Here, a novel NiCo2S4 with reticulated hollow spheres assembled from rod-like structures was prepared by a one-pot solvothermal method and its formation mechanism was discussed. Moreover, comparison of NiCo2S4 materials from different experiment conditions as biosensors was investigated by electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV), and the best one that was reticulated hollow spheres assembled from rod-like structures NiCo2S4 has been successfully employed as a matrix of AChE immobilization for the special structure, superior conductivity and rich reaction active sites. When using common two kinds of organophosphate pesticides (OPs) as model analyte, the biosensors demonstrated a wide linear range of 1.0×10-12-1.0×10-8gmL-1 with the detection limit of 4.2×10-13gmL-1 for methyl parathion, and 1.0×10-13-1.0×10-10gmL-1 with the detection limit of 3.5×10-14gmL-1 for paraoxon, respectively. The proposed biosensors exhibited many advantages such as acceptable stability and low cost, providing a promising tool for analysis of OPs.