Molecularly imprinted electrochemical sensing platform for 2-Aminoadipic acid, a diabetes biomarker

Abstract A silylatedgraphene oxide (Si-GO) based electrochemical sensor was fabricated for the selective and specific detection of a diabetes biomarker 2-Aminoadipic Acid (2-AAA). The fabrication was preceded by molecularly imprinting technology accompanied by electrochemical sensing. Different molecularly imprinted polymers (MIPs) were prepared using different monomers such as 2-Acrylamido-2-methylpropanesulfonicacid (AMPS), Methacrylic acid (MAA) and Vinyl pyridine (VPy) with different ratios. Ethylene glycol dimethacrylate (EGDMA) and potassium peroxodisulphate (KPS) were used as a cross linker and an initiator, respectively. Cyclic voltametry (CV), differential pulse voltametry (DPV) and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical behavior of the modified electrode. Modified electrode can be prepared by the surface modification of a glassy carbon electrode (GCE) with MIP (MIP/GCE) by drop-casting method. The prepared materials were characterized using Fourier Transforms Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FE-SEM). The modified MIP electrode shows an enhanced redox peak with a peak potential difference of 0.70 V with redox current of 0.015 mA, which indicates the presence of complementary active sites of 2-AAA in MIP. The NIP electrode shows a weaker redox peak difference compared to MIP. The optimum time response and pH were found to be 15 min and 5, respectively. DPV analysis gives good linearity with R2 value 0.9932. Limit of detection (LOD) and Limit of quantification (LOQ) were obtained as 0.40 × 10−11 and 1.34 × 10−11 M, respectively.