Signal enhancement of cetyltrimethylammonium bromide as a highly-sensitive sensing strategy for tetrabromobisphenol A

It is quite important to monitor tetrabromobisphenol A (TBBPA) in environmental samples due to its wide existence and high toxicity. Herein, a highly-sensitive electrochemical method was developed for the determination of TBBPA based on the strong signal enhancement effects of cetyltrimethylammonium bromide (CTAB). In pH 7.5 phosphate buffer, an irreversible oxidation peak with low height is observed for TBBPA on the surface of a carbon paste electrode (CPE), and the oxidation wave is improved greatly after addition of a low concentration of CTAB. The great peak current enlargements indicate that CTAB exhibits remarkable enhancement effects toward TBBPA oxidation. The enhancement mechanism of CTAB was investigated using electrochemical impedance spectroscopy and chronocoulometry. It is found that the existence of CTAB obviously increases the accumulation efficiency of TBBPA and facilitates its electron transfer. The linear range of this new sensing system is from 2.5 to 800 nM, and the detection limit is 0.99 nM. It was used in water sample analysis, and the recovery value was over the range from 95.74% to 102.6%.