Selective and sensitive glycoprotein detection via a biomimetic electrochemical sensor based on surface molecular imprinting and boronate-modified reduced graphene oxide

Glycoproteins are closely associated with the occurrence of diverse diseases, and they have been used as biomarkers and therapeutic targets in clinical diagnostics. The selective and sensitive sensing of glycoproteins still remains a challenge. Herein, we describe a biomimetic electrochemical sensor based on a novel boronate-modified graphene-molecular imprinted polymers composite (BGR@MIP) as recognition element that is well suited for detecting glycoproteins selectively and sensitively. Boronic acid functionalized reduced graphene oxide (BGR) bearing a covalent ester linkage to glycoprotein via boronate affinity was synthesized and used as supporting matrix for preparing graphene surface imprinted composite by sol-gel polymerization of organic silanes. The fabrication process of the BGR@MIP sensor was monitored by differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) using [Fe(CN) 6 ] 3−/4− as probe. The combination of boronate affinity and molecularly imprinting effect endowed the sensor with remarkable selectivity for the template glycoprotein (ovalbumin, OVA). Under optimized experimental conditions, the proposed sensor exhibited a good linear response to OVA in the concentration range of 1.0 × 10 −10  mg mL −1 to 1.0 × 10 −4  mg mL −1 with detection limit of 2.0 × 10 −11  mg mL −1, which outperformed other previously reported OVA detecting methods High stability and good reproducibility was also demonstrated. In addition, this sensor was successfully applied to the monitoring of OVA in biological fluids.