Photoelectrochemical determination of malathion by using CuO modified with a metal-organic framework of type Cu-BTC

A photoelectrochemical (PEC) sensor was constructed for the detection of non-electroactive malathion. It is based on the use of a hierarchical CuO material derived from a Cu-BTC metal-organic framework (where BTC stands for benzene-1,3,5-tricarboxylic acid). The modified CuO was obtained by calcination of Cu-BTC at a high temperature (300 degrees C) and possesses a high photocurrent conversion efficiency. Under irradiation with visible light and in the presence of malathion, the formation of the CuO-malathion complex on the CuO gave rise to an increase in steric hindrance. This results in a decrease in photocurrent. This novel PEC detection method has a lower detection limit of 8.6 x 10(-11) mol L-1 and a wide linear range (1.0 x 10(-10) similar to 1.0 x 10(-5) mol L-1).