Cortisol Stress Biosensor Based on Molecular Imprinted Polymer

Abstract

The molecular imprinted polymer (MIP) technique was applied to receptors that could imitate the performance of natural anti-cortisol antibody with high stability. Cortisol-molecular imprinted polymer (cortisol-MIP) was obtained using the multi-step swelling and polymerization protocol with cortisol as a target molecule. The suitable ratio of methacrylic acid:acrylamide :cortisol which allowed the formation of 642.3 ± 35.8 nm homogenous particles was 2:1:1. Cortisol-MIP was integrated to the sensor. It was coated on the disposable screen-printed carbon electrode (SPCE) for portable electrochemical analysis. The physical properties of Cortisol-MIP were characterized by means of electron microscope techniques. The binding characteristics were evaluated via covalent patterns changing in FTIR spectra which were related to voltammetry responses. The SPCE modified with cortisol-MIP was able to perform various detection ranges from 1.28 to 20 nM and the high selectivity compared to three other glucocorticoid analogs.

Keywords

• core shell molecular imprinted polymer (Cs-MIP)
• cortisol
• screen printed carbon electrode (SPCE)