Recent Application of Metal-Organic Frameworks in an Electrochemical Immunosensor

An electrochemical immunosensor combines electrochemical technology with an immune response to disease biomarkers with characteristics of high sensitivity, simple instrumentation, and flexible methods. Metal-organic frameworks (MOFs) belong to a class of porous materials with a periodic crystalline network structure. Generally, the metal ions in MOFs are electrochemically active. MOFs have well-ordered pores and a large specific surface area, which makes it easy to immobilize antibodies, promoting the application of MOFs in electrochemical immunosensors whose selectivity toward targeted proteins and bacteria can be greatly improved through introducing antigens or antibodies inside MOFs. MOFs have been regarded as promising carriers to effectively increase antibody loading; they sometimes showed favorable enzyme-like catalytic activity as well. In this review, we first introduced the response forms of electrochemical immunosensors, followed by the discussion of the application of MOFs in electrochemical immunosensors in the last 5 years based on the six electrochemical detection methods. Some important prospects and further challenges in this area were briefly discussed in the end.