Background: Considering that BPA has emerged as a major public health
issue, there is an urgent need to establish a simple, effective, and highly sensitive
method for monitoring the levels of BPA. The aim of this work was to construct
an electrochemical sensor for the detection of BPA by the combination of molecularly
imprinted technique and MWCNTs. The optimization of test conditions and the performance
of the imprinted sensor were discussed. The application of the sensor in real
water samples was evaluated.
Methods: The sensor was prepared by electropolymerizing o-phenylenediamine with
bisphenol A after depositing carboxylfunctionalized multi-walled carbon nanotubes
onto the surface of a glassy carbon electrode. The template can be quickly removed in
methanol–acetic acid (1:1, v/v) solution. The formation of PoPD film was monitored by FT-IR spectra.
The morphological structures of the modified electrodes were tested by SEM. K3[Fe(CN)6] served as an
electrochemical probe in this work. Cyclic voltammetry and linear sweep voltammetry were employed for
the electrochemical characterization of the sensor.
Results: The molecularly imprinted polymer based sensor displayed an excellent recognition capacity
toward BPA compared with other structurally similar molecules, and the existence of some inorganic ions
and organic compounds has no obvious effect on the determination of the analyte. Additionally,
the decrease of the peak current of K3Fe(CN)6 was proportional to the BPA concentration in the range of
4.0 x 10-7 to 8 .0 x 10-5 mol L-1 with a limit of detection of 6.0 x 10-8 mol L-1. The prepared sensor also
showed stable repeatability. The results in real samples obtained by the proposed method agreed with
those obtained from high performance capillary electrophoresis method.
Conclusion: An electrochemical sensor for BPA based on electropolymerization of the oPD in the presence
of BPA on the MGCE has been successfully fabricated. When the resulting sensor was applied to the
determination of BPA, it presented high sensitivity, stability and selectivity. In addition, the fabrication
procedure was quite simple. The use of MWCNTs enhanced the sensitivity of detection and resulted in a
better LOD; in combination with the specific selectivity of the molecularly imprinting technique, the proposed
sensor provided a bright potential for the determination of BPA in practical samples.