Abstract
•Chemical polymerization-ultrasonication assisted synthesis of PANI_AuNPs composite.•Determining the electron transfer kinetics for BPA oxidation through Butler-Volmer theory, Tafel plot, and convoluted potential sweep voltammetry (CPSV) analysis.•Discussing the corresponding BPA oxidation reaction mechanism.•Wide linear range from the nanomolar to micromolar region (0.003 to 0.064 µM and 0.075 to 45.69 µM), with LOD as low as 0.4 nM.•Studying practical applicability of the sensor for detecting bisphenol A from tap water, bottle water, and beverage samples.
In this work, a conducting polymer and nanometal composite electrocatalyst was prepared for the sensitive detection of bisphenol A (BPA) over a wide concentration window. Polyaniline (PANI) was first prepared from aniline through a chemical method, and gold nanoparticles (AuNPs) were embedded with the prepared PANI via ultrasonication to obtain the PANI_AuNPs electrocatalyst. The morphological, chemical, and electrochemical properties of the electrocatalyst were then determined, and BPA oxidation was investigated with the help of electroanalytical techniques to understand the electron-transfer process occurring at the PANI_AuNPs interface. The results showed that BPA was oxidized through a multistep electron-transfer process without any intermediate chemical step, and the rate-determining step was the second electron-transfer step. The oxidation proceeded as a 2e–/2H+ process with an electron-transfer coefficient of ≈0.69. These results indicate that the PANI and AuNPs work synergistically to promote the electron transfer from BPA. The quantitative analysis gave a broad linear range and a low limit of detection of 0.4 nM. The sensor was also tested for the detection of BPA in tap water, bottled water, and a canned beverage for real sample analysis.
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