Stable and Sensitive Amperometric Determination of Endocrine Disruptor Bisphenol A at Residual Metal Impurities Within SWCNT

A simple and attentive method was attempted for the determination of endocrine disruptor molecule, Bisphenol A (BPA) using residual metal impurity act as a reactant present in as received SWCNT. The electrochemical behavior of BPA oxidation and its reaction mechanism was investigated by cyclic voltammetry using as received SWCNT modified on glassy carbon electrode (SWCNT/GCE) and the obtained results were compared with bare GCE. The SWCNT/GCE showed high electrocatalytic activity, sensitivity, stability and more importantly not much surface fouling compared with bare GCE. This is because of the formation of electroactive quinone and catechol as byproducts on SWCNT/GCE during electro-oxidation of BPA. More interestingly, the electrochemically acid treated SWCNT/GCE not showed any characteristic oxidation and reduction peaks during electro-oxidation of BPA which indicates that the presence of a residual metal impurity in SWCNT plays a vital role in electro-oxidation of BPA. The amperometric detection of BPA oxidation on SWCNT/GCE showed excellent stability and good linear response from the wide range of concentration of 10-100M. The limit of detection and sensitivity of BPA electro-oxidation on SWCNT/GCE is to be 7.3M (S/N=3) and 0.6494A/Mcm(2) respectively. Finally, the fabricated sensor using SWCNT/GCE was successfully applied for the detection of BPA in plastic water bottles with excellent recovery range from 98-102%.