Sensitive detection of glyphosate based on a Cu-BTC MOF/g-C3N4 nanosheet photoelectrochemical sensor

A photoelectrochemical (PEC) sensor based on hierarchically porous Cu-BTC/g-C 3 N 4 nanosheet (Cu-BTC/CN-NS, BTC = benzene-1,3,5-tricarboxylic acid) material was constructed for the first time. As a composite material, the hierarchically porous Cu-BTC can help to efficiently capture suitable pesticide molecules and accelerate signal transmission, while CN-NS possesses good optical performance. Under the irradiation of visible light, the Cu metal center can coordinate with the added glyphosate to form Cu-glyphosate complexes, leading to the increased steric hindrance of electron transfer and consequently resulted in an obvious decrease in photocurrent . Through this strategy, the constructed sensor can realize the detection of glyphosate from non-electroactive to electroactive. The results indicate that this photoelectrochemical sensor has a low detection limit of 1.3 × 10 −13  mol L −1 and a wide detection range (1.0 × 10 −12 –1.0 × 10 −8  mol L −1 and 1.0 × 10 −8 ∼ 1.0 × 10 −3  mol L −1 ). Furthermore, this Cu-BTC/CN-NS based sensor has the characteristics of short detection time and easy operation. It has great potential applications in photoelectrochemical analysis.