Electrochemical biosensor based on CuPt alloy NTs-AOE for the ultrasensitive detection of organophosphate pesticides.

The electrode material is vital for the performance of the electrochemical biosensor. Lately, many nanomaterials have been developed to improve the sensitivity and detection efficiency of the biosensors. In this work, a kind of one-dimensional nanomaterials, the CuPt alloy nanotubes with an open end (CuPt alloy NTs-AOE), was explored. The nanotubes with an open end can provide a larger electrochemical active surface area and more active sites for the immobilization of enzyme. The CuPt alloy displays excellent conductivity and catalytic activity. In addition, the Cu shows the great affinity to thio-compounds, which can greatly enhance the detection efficiency and sensitivity. As a result, the prepared biosensor demonstrates the wider linear range of 9.98×10-10 - 9.98×10-5 g/L for fenitrothion and 9.94×10-11 - 9.94×10-4 g/L for dichlorvos (as model OPs ) and with the lower detection limit of 1.84 ×10-10 g/L and 6.31×10-12 g/L (S/N = 3), respectively. Besides, the biosensor has been used to detect the real samples and obtains satisfactory recoveries (95.58 % - 100.56 %).