C-reactive Protein and Glucose Electrochemical Sensors Based on Zr(IV) Organic Framework with 2,5-thiophenedicarboxylate Anion

Several reports reveal that high level of C-reactive protein (CRP) in serum enhances venture of diabetes. In this article, we presented a platform which blended Zr(IV)-organic framework with 2,5-thiophenedicarboxylate ligand (Zr-tdc) and ionic liquid (IL) to form a steady composite membrane on the carbon paste electrode (CPE). The platform was applied to CRP and glucose biosensors which were connected with diabetes and displayed well performances. Firstly, a sensitive immunosensor for label-free and direct detection of CRP was developed at Zr-tdc/IL modified electrode. Under optimal conditions, differential pulse voltammetry (DPV) response showed the low detection limit of CRP was 0.2 ng/mL. Secondly, the glucose biosensor immobilized glucose oxidase (GOX) was constructed and studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and amperometric response. The Michaelis–Menten constant (KM) of immobilized GOX was 0.16 mM, and the detection limit was 2.7 μM for glucose. Two novel biosensors displayed well selectivity, stability and lower detection limit. This work improved the performance of electrochemical sensing and expand the utilization of the material by carrying on the effective immobilization of enzyme and antibody.