A surfactant-mediated sol-gel method for the preparation of molecularly imprinted polymers and its application in a biomimetic immunoassay for the detection of protein.

Molecularly imprinted polymers have demonstrated tremendous potential in the immunoassay as alternatives to biological antibodies. However, the production of molecularly imprinted polymers for protein remains great challenges because of structural complexity and organic solvent instability. In addition, non-specific binding sites in the molecularly imprinted polymers debase the feasibility of it as alternative to antibodies for immunoassay. Here, a surfactant-mediated sol-gel system in an aqueous environment was designed to produce the molecularly imprinted polymers for protein. A blocked strategy was introduced to decrease non-specific cross-reactivity and to improve the selectivity. The developed products were characterized by infrared spectroscopy, scanning electron microscope, transmission electron microscope, X-ray photoelectron spectroscopy, and vibrating sample magnetometer, respectively. The obtained molecularly imprinted polymers exhibited desirable specific recognition towards the target and a biomimetic immunoassay method was developed. The method exhibited a good linear response to human serum albumin in a concentration range of 1-100 μg mL-1. The limit of detection of this method was 0.3 μg mL-1 (3s/K), and good recoveries ranging from 85.4-104.5% were achieved. This study demonstrated that the molecularly imprinted polymers prepared by the surfactant-mediated sol-gel method can produce high selectivity materials, which had great potential to replace antibodies in a biomimetic immunoassay.