Bimetallic nickel/cobalt metal-organic framework-based electrochemical sensor for trace level detection of IgG in simulated human blood serum

Electrochemical sensing is a widely used technique for the detection of biomolecules because of its low cost, high sensitivity, and versatility in terms of the various techniques that can be employed. In this study, we report a facile, cost-effective, and highly selective bimetallic Ni/Co-MOF (Nickel/Cobalt-Metal Organic Framework) on Nickel foam (NF) based electrochemical sensor for the trace-level detection of IgG (Human Immunoglobulin) antibodies in the human blood serum. In this direction, we used a simple and efficient solvothermal method to synthesize the Ni/Co-MOF, and the morphological, structural, and chemical states of the elements are studied using different material characterization techniques like TEM, FESEM, XRD, XPS, etc. The Ni/Co-MOF modified NF sensor showed a dynamic range of detection (30 fM to 10 nM) having superior sensitivity of 28 µA cm−2 mol−1 with a lower limit of detection 27.2 fM. Ni/Co-MOF/NF is highly selective over other interfering species (UA, Cl−, Ca2+, Urea, Sulphate, BSA and HAS). Real-time analysis was done using the DPV technique by the standard addition method and the sensor shows an excellent recovery percentage ̴ 97 to 98 %. Also, the addition of Ni2+ to Co enhances the electrochemical properties of a material by raising the valence of Ni2+ in Ni/Co-MOF by transferring partial electrons from Ni2+ to Co2+. The work presented here confirms Ni/Co-MOF/NF as a flexible, high-performance electrode that can be used to detect other biomolecules used in clinical diagnosis and biomedical research.