Ultrasensitive and ultrawide range electrochemical determination of bisphenol A based on PtPd bimetallic nanoparticles and cationic pillar[5] arene decorated graphene

This study proposed an ultrasensitive and ultrawide range electrochemical sensing platform based on PtPd bimetallic nanoparticles (PtPd NPs) and cationic pillar [5] arene (CP5) decorated graphene for bisphenol A (BPA). CP5-decorated reduced graphene oxide (RGO) (CP5@RGO) was synthesized via a reported assay. PtPd NPs-loaded CP5@RGO nanocomposites (PtPd-CP5@RGO) were then prepared through a simple approach at room temperature. The as prepared materials were characterized by various technologies, including EDX, FT-IR, XRD, TG analysis, XPS, zeta potentiometer, TEM, and AFM. The current response of PtPd-CP5@RGO modified glassy carbon electrode (GCE) to BPA oxidation was higher than that of Pt NPs-, Pd NPs-, or CP5-modified GCE. An electrochemical sensor based on PtPd-CP5@RGO-modified GCE was utilized to determine BPA through differential pulse voltammetry. The sensor yielded the wider linear ranges of 0.01-50 mu M and 50-1000 mu M, respectively, with a lower limit of detection of 3.3 nM (S/N = 3) for BPA determination. The constructed sensor showed some advantages, such as satisfactory reproducibility, good stability, and excellent selectivity, which was applied to determine BPA concentration in real samples. BPA and CP5 likely formed a stable complex mainly via supramolecular interactions, such as electrostatic and hydrophobic interaction.