Molecularly imprinted colloidal array with multi-boronic acid sites for glycoprotein detection under neutral pH

Glycoproteins play vital roles in living organisms and often serve as biomarkers for some disease. However, due to the low content of glycoprotein in biological fluids, selective detection of glycoproteins is still a challenging issue that needs to be addressed. In this study, molecularly imprinted colloidal array with multi-boronic acid sites for glycoprotein detection under physiological pH was proposed. Monodispersed glycoprotein imprinted particles (SiO2@PEI/MIPs) was first prepared based on surface imprinting strategy using horseradish peroxidase (HRP) as template, and polyethyleneimine (PEI) was used to increase the number of boronic acid groups. The binding experiment indicated that the SiO2@PEI/MIPs hold satisfactory adsorption capacity (1.41 lmol/g), rapid adsorption rate (40 min) and preferable selectivity toward HRP. Then the SiO2@PEI/MIPs was assembled into close-packed colloidal array to construct a label free optical sensor (denoted as GICA). Benefiting from the high ordered photonic crystal structure, binding of HRP onto the GICA could be directly readout from the changes in structure color and diffracted wavelength. The structure color of the GICA changed from bright blue to yellow with the diffraction wavelength red shifted 59 nm when the HRP concentration increased from 2.5 to 15 lmol/L. Importantly, the GICA was capable of detecting HRP from human serum samples. All those results indicated the potential of the GICA for naked-eye detection of glycoprotein. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

Glycoproteins are important biomarkers in living organisms, but selective detection remains a challenge due to low content in biological fluids. A molecularly imprinted colloidal array with multi-boronic acid sites was proposed for glycoprotein detection, showing promising results in terms of adsorption capacity and selectivity. The label-free optical sensor constructed from this array demonstrated the potential for naked-eye detection of glycoprotein, with successful detection from human serum samples.