Determination of ovalbumin sensing response of protein-imprinted bilayered hydrogel strips via measurement of mechanically driven bending angles based on swelling-induced deformation

Novel detection method has been developed to explore changes in mechanical bending angles on a bilayer of polyethylene terephthalate (PET) and molecularly imprinted polymer (MIP). For an ovalbumin (OVA)-imprinted hydrogel layer, functional monomers were employed to achieve sufficient binding effect in the polymer matrix. The OVA amount added in the MIP precursor solution and the dimensions of OVA-imprinted hydrogel (MIH) strips were controlled to maximize the change in bending angles as an OVA sensing response within a valid detection range. The sensing behaviors were determined by monitoring the difference in the bending angles via protein adsorption based on the swelling-induced deformation of the OVA-extracted hydrogel (E-MIH) strip. The equilibrium adsorption capacity of the E-MIH strip was calculated via the Bradford protein assay. The detection limit, quantification limit, and imprinting factor were calculated. To compare the selectivity coefficients, the adsorption behaviors of three proteins were investigated. Finally, the reusability of the E-MIH strip was explored via repeated adsorption and extraction. Based on the results, the E-MIH strips demonstrated a promising protein sensing platform monitoring mechanical bending angles affected by swelling deformation. Graphical abstract