PEDOT: PSS/AuNPs-Based Composite as Voltammetric Sensor for the Detection of Pirimicarb

An electrochemical sensor for the pesticide Pirimicarb (PMC) has been developed. A screen-printed electrode (SPCE) was used and modified with the conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT) and gold nanoparticles (AuNPs) to enhance electrochemical proprieties. Electrode characterizations were performed using scattering electron microscopy (SEM) and cyclic voltammetry (CV). With the SPCE/PEDOT:PSS/AuNPs modified electrode, a new peak at 1.0 V appeared in the presence of PMC related to the PMC oxidation. To elucidate the mechanism of PMC oxidation, Gas Chromatography-Mass Spectrometry (GC-MS), where two major peaks were identified, evidencing that the device can both detect and degrade PMC by an electro-oxidation process. Exploring this peak signal, it was possible the sensor development, performing detection from 93.81-750 mu mol L-1, limits of quantification (LOQ) and detection (LOD) of 93.91 mu mol L-1 and 28.34 mu mol L-1, respectively. Thus, it was possible to study and optimization of PMC degradation, moreover, to perform detection at low concentrations and with good selectivity against different interferents using a low-cost printed electrode based on graphite modified with conductive polymer and AuNPs.

Automated summary

An electrochemical sensor utilizing a screen-printed electrode modified with conducting polymer and gold nanoparticles has been developed for detecting and degrading the pesticide Pirimicarb (PMC). The sensor showed a new peak at 1.0 V in the presence of PMC, indicating its oxidation. Gas Chromatography-Mass Spectrometry (GC-MS) was used to elucidate the mechanism of PMC oxidation, which confirmed the ability of the sensor to detect and degrade PMC through an electro-oxidation process. The sensor exhibited a detection range of 93.81-750 μmol L-1 with limits of quantification (LOQ) and detection (LOD) of 93.91 μmol L-1 and 28.34 μmol L-1, respectively, and demonstrated good selectivity against interferents.