Double recognition of dopamine based on a boronic acid functionalized poly(aniline-co-anthranilic acid)–molecularly imprinted polymer composite

Abstract

In this work, we report a competitive sensor performing “double recognition” for the specific capture of dopamine (DA) with the combination of boronic acid functional groups and molecularly imprinted cavities based on poly(aniline-co-anthranilic acid) (PANANA) as the support material. This novel imprinting receptor bearing a covalent ester linkage to DA via boronic acid functional groups was prepared and applied as a recognition element in the construction of the electrochemical sensor. For the first time, aminophenylboronic acids (APBAs) and vinyl groups were both introduced onto the surface of PANANA nanomaterials. Then, selective copolymerization of acrylamide and ethylene glycol dimethacrylate (EGDMA) in the presence of the template DA was further achieved at the surface of APBA and vinyl group functionalized PANANA. The double recognition through the functional groups (boronic acids) and the shape of the cavities endowed this sensor with a specific affinity for the template DA in the presence of other interferents, such as norepinephrine (NE), epinephrine (EP), ascorbic acid (AA) and uric acid (UA). Moreover, the results obtained from a series of electrochemical experiments proved that this receptor had a good adsorption capacity and a fast mass transfer rate for DA. Thus, a novel electrochemical sensor with good selectivity and sensitivity was constructed with a linear response to the DA concentration in the range from 1.0 × 10⁻⁸ to 1.0 × 10⁻⁵ M and a detection limit of 3.33 × 10⁻⁹ M (S/N = 3). Besides, this novel electrochemical sensor was successfully applied to the detection of DA in DA injected and human plasma samples.