Pyrrole–phenylboronic acid: A novel monomer for dopamine recognition and detection based on imprinted electrochemical sensor

A molecular imprinting polymer (MIP) based electrochemical sensor was successfully prepared for dopamine (DA) recognition and detection using pyrrole–phenylboronic acid (py–PBA) as a novel electropolymerized monomer. py–PBA could form cyclic boronic ester bond with DA, thus endowing a double recognition capacity of the sensor to DA in the combination of the imprinted effect of MIP. Compared with the sensor prepared using pyrrole or phenylboronic acid as electropolymerized monomer, the present sensor exhibited a remarkable high imprinted factor to DA. The influence factors including pH value, the mole ratio between monomer and template molecule, electropolymerization scan rate, and scan cycles of electropolymerization process were investigated and optimized. Under the optimal conditions, the sensor could recognize DA from its analogs and monosaccharides. A linear ranging from 5.0×10−8 to 1.0×10−5 mol/L for the detection of DA was obtained with a detection limit of 3.3×10−8 mol/L (S/N=3). The sensor has been applied to analyze DA in injection samples with satisfactory results.