Preparation of an electrochemical sensor based on the surface molecular imprinting technique and its application in the detection of proteins

Accurate quantification of protein concentrations in vivo holds pivotal significance in biomedical research, clinical diagnostics, and health management. The conventional methods face limitations like complex procedures, high costs, and tedious sample preparation. Therefore, developing rapid and user-friendly protein detection techniques is essential. In this study, two modified electrochemical molecularly imprinted polymer electrochemical sensors (MIP/AuNPs/GCE and MIP/GA@CS/AuNPs/GCE) were prepared for the detection of the clinically relevant protein biomarkers, such as BSA, Histone, IGF-1, CRP, HSA, GSH, and β-LG. The result shows that the MIP/AuNPs/GCE sensor configuration exhibited selective recognition exclusively for proteins containing free sulfhydryl groups through the “S-Au” bond. Based on this, we added chitosan (CS) and glutaraldehyde (GA) to the sensor system to build a general detection platform for protein. The optimized MIP/GA@CS/AuNPs/GCE sensor demonstrated broad-spectrum protein detection capability, independent of sulfhydryl group presence, as confirmed through validation studies using model analytes. The addition of chitosan and glutaraldehyde can form hydrogen bond and Schiff base with protein respectively, which resulted in efficient protein immobilization, wide range of detection, high sensitivity, and generic detection of proteins. The developed method is applicable to the detection of a wide range of protein biomarkers, which can provide an innovative method for clinical diagnosis, bioanalytical chemistry, and protein separation and extraction.