Fabrication of a molecularly imprinted silylated graphene oxide polymer for sensing and quantification of creatinine in blood and urine samples

A graphene oxide (GO)-based electrochemical sensor, trimethyl silane propyl methacrylate-GO copolymerized with 2-hydroxymethacrylate/methyl methacrylate [TMSPMA-GO-co-HEMA/MMA] to detect creatinine (Cn) was fabricated by molecular imprinting technology followed by electrochemical detection. Electrochemical measurements were made by cyclic voltammetry and differential pulse voltammetry. Polymerization of GO-TMSPMA was achieved in the presence of Cn with ethylene glycol dimethacrylate as crosslinker and 2,2'-azobisisobutyronitrile as initiator. The physical and chemical properties of the resulted material were characterized by FTIR spectroscopy, NMR spectroscopy, Raman spectroscopy, XRD, SEM, and AFM. The effective pH for the response of the sensor material was found to be 7.4. The electrode exhibited a response time of similar to 2 min, and the limit of detection obtained was 0.1878 mg/dL and the limit of quantification was 0.6122 mg/dL. The fabricated molecular imprinted polymer sensor could be reused several times without decrease in its selectivity. The feasibility of the present sensor in real time was successfully verified by analyzing Cn level in human blood serum and urine samples. By comparing the present sensing method with the traditional Jaffe method, we obtained a linear correlation with a coefficient of 0.9928; this implies that the present biosensor possesses a sensitivity comparable to that of the traditional laboratory method.