Synthesis and Characterization of Sensitive Molecular Imprinting Electrochemical Sensor Based on Chitosan Modified HPSNS-NH2@Au for Detection of 2,4-D

Aminated layered porous silica supported gold nanoparticle (HPSNs-NH 2 @Au) materials were facilely compounds, and sensitive electrochemical sensor was constructed by electropolymerization method. The HPSNs-NH 2 @Au nanocomposites were directly synthesized by two-steps hydrothermal synthesis method. The electrochemical performance of aminated layered porous silica (HPSNs-NH 2 ) nanocomposites are effectively improved by the Au nanoparticle loading. The porous structure of HPSNs-NH 2 @Au provided more imprinting recognition sites for template molecules, while the fluffy HPSNs-NH 2 and gold nanoparticles synergy to promote electron transfer. The effective specific surface areas and excellent electrical conductivity endow HPSNs-NH 2 @Au with a series of electrochemical properties, which confirmed the uniqueness of nanocomposites and greatly enhance the current responses. Further using molecularly imprinted polymers (MIPs) as the recognition units for electropolymerization. In this work constructed a molecularly imprinted polymer electrochemical sensor with good sensitivity for the target 2,4-dichlorophenoxy acetic acid (2,4-D) detection. Under optimized conditions, The prepared MIPs/HPSNs-NH 2 @Au sensor showed significant detection performance with 2,4-D concentration in the range of 10 -4 to 10 -11 mol L -1 and the LOD was 1.07×10 -13 mol L -1 (S/N = 3). Moreover, the sensor has excellent selectivity in the presence of interfering substances. 2,4-D was included in actual samples have been quantitative determination with a satisfactory recovery rate, which indicating potential application value for the environment.