Pesticide Aptamer Sensor Based On Hydroxylated Black Phosphorus/Polymer Composites

Black phosphorus has puckered honeycomb configuration,great biocompatibility,high carrier mobility and tunable bandgap,which plays an important role in improving the sensitivity and selectivity of biosensor.However,black phosphorus isolated by traditional methods is easily oxidized and degraded by air,with poor stability,which limits its application in sensor.Therefore,developing a method of modification and functionalization of black phosphorus has important research value to improve the performance of biosensor based on black phosphorus.In this study,we are devoted to prepare high-quality black phosphorus nanomaterials and combined with the significant specificity aptamer to construct a kind of rapid and sensitive aptamer electrochemical sensor for the detection of pesticide residues,which provides a reliable,effective and rapid method for the detection of pesticide residues in the environment and agricultural products,and is of great significance for evaluating the environmental risk caused by single-component pesticide residues.1.A method for preparing high quality black phosphorus nanosheets was investigated.Firstly,the hydroxylated black phosphorus nanosheets were prepared by liquid phase ultrasonic exfoliation.The changes of black phosphorus nanosheets before and after modification were compared by material characterization and electrochemical testing.The experimental results show that the modified black phosphorus nanosheets has a zigzag protruding morphology,which can provide more active sites and charge storage channels,thus increasing the carrier mobility and improving the energy storage performance of black phosphorus nanosheets,while greatly retaining the anisotropic physical properties of black phosphorus with the characteristics of double-layer capacitance of multilayer black phosphorus.2.An aptamer electrochemical sensor based on hydroxylated black phosphorus/poly-L-lysine composite was constructed for the detection of malathion.The experimental results show that the linear range of the sensor is 0.1 p M to 1 μM,the detection limit is 2.805 f M,and the recovery range of the actual sample is 92.6% to 96.6%,which can be applied to the trace detection of malathion.3.An aptamer electrochemical sensor based on hydroxylated black phosphorus/thionine/poly-L-lysine composite was constructed for the detection of acetamiprid.The experimental results show that the linear range of the sensor is 10 f M to 1 μM,the detection limit is 9.407 f M,and the recovery of the actual sample is more than 95%,which can be applied to the trace detection of acetamiprid.