The preparation of two molecularly imprinted electrochemical sensors based on gold nanoparticles and glutaraldehyde and their application in protein detection

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, including BSA, Histone, IGF-1, CRP, HSA, GSH, and β-LG. MIP/AuNPs/GCE were prepared by simple modification of AuNPs onto the GCE, which can detect proteins containing free sulfhydryl groups only. To broaden the detection scope, MIP/GA@CS/AuNPs/GCE were prepared, modified by chitosan (CS) and glutaraldehyde (GA) to form hydrogen bonds and Schiff bases with proteins, thereby enabling efficient protein immobilization. The result shows that the MIP/AuNPs/GCE sensor can only detect BSA, HSA, GSH and β-LG, which have the free sulfhydryl groups. While the MIP/GA@CS/AuNPs/GCE sensor can detect all seven proteins. Combined with molecular imprinted polymer technology, the optimized MIP/GA@CS/AuNPs/GCE sensor exhibited a broader capability for protein detection. The MIP/GA@CS/AuNPs/GCE sensor demonstrated excellent selectivity, a wide detection range, and high sensitivity, with a detection limit down to the fM level. This method is applicable for the detection of protein biomarkers, providing innovative technical support for clinical diagnosis, bioanalytical chemistry, and protein separation and extraction. Section Graphical