Colorimetric Nanozyme Sensor Array Based on Metal Nanoparticle-Decorated CNTs for Quantification of Pesticides in Real Water and Soil Samples

Pesticides have become a concern to the environment and human health, since they are frequently employed to control pests and regulate plant growth. Although array-based pattern recognition has been demonstrated to be a successful method for identifying a variety of analytes, developing sensing components that possess a desirable surface diversity remains a difficult task. Herein, we fabricated a metal nanoparticle-decorated CNT (MDC) nanozyme in the presence of a cationic receptor to produce diverse noncovalent interactions when various pesticides were adsorbed on the MDCs, which resulted in the enhancement of their peroxidase-mimicking activities with different degrees, and utilized it as a colorimetric sensor array for pesticide identification. The designed MDC sensor array could successfully distinguish eight pesticides that exhibited different fingerprint-like sequences at a concentration of 10 mu M or successfully segregated CBZ, DTM, and ISP pesticides having a linear range varying from 1 to 8 mu M and quantified as low as 10.8, 28.8, and 16.8 nM with R-2 values of 0.983, 0.949, and 0.977, respectively. Very interestingly, two pesticides having similar structures (CBZ and ISP) have been precisely discriminated by a sensor array without any overlapping. Additionally, the effective segregation of pesticides in spiked soil and water samples without cross-classification demonstrated the practicability of the MDC sensor array.