A highly sensitive electrochemical sensor for bisphenol A using cetyltrimethylammonium bromide functionalized carbon nanohorn modified electrode

Abstract

A highly sensitive electrochemical bisphenol A (BPA) sensor was developed based on cetyltrimethylammonium bromide (CTAB) functionalized carbon nanohorn (CNH) modified electrode. CNH was carboxylated and could well disperse in water, and CNH-modified electrode showed enhanced electron transfer and high conductivity. Carboxylic CNH was functionalized with a cationic surfactant (CTAB) via the electrostatic interaction. CTAB functionalized CNH (CTAB-CNH) suspension was dropped onto glassy carbon electrode (GCE) to fabricate CTAB-CNH/GCE. Combined with preconcentration of BPA in the long alkane chain of CTAB via hydrophobic interaction and electrocatalytic activity of CNH, CTAB-CNH/GCE had high electrochemical response toward the oxidation of BPA, and an electrochemical BPA sensor was constructed on CTAB-CNH/GCE using differential pulse voltammetry. Under optimal experimental conditions, the designed sensor exhibited a wide linear response to BPA ranging from 0.01 to 30 μmol/L with a low detection limit of 5.6 nmol/L at a signal-to-noise ratio of 3. The proposed sensor has good reproducibility, reusability, and anti-interference properties, and was successfully applied to detect BPA in real samples with satisfactory results. This convenient and sensitive sensor could be readily extended toward monitoring other small toxic or harmful molecules in food and environment samples.