Metal-organic framework-based electrochemical aptasensors for detecting cancer biomarkers

Developing an efficient biosensor with high sensitivity and selectivity is significant for the early diagnosis of cancers to improve the survival rate of cancer patients. Metal-organic framework (MOF)-based electrochemical aptamer biosensors have attracted wide attention in detecting tumor markers. MOF, as a porous crystal material, consists of metal ions and organic ligands with the unique advantages of large surface area, tunable pore scales, simple synthetic method, and good adsorption capabilities. Because of its weak specificity, MOF is often combined with aptamers to meet the selectivity of electrochemical sensors. Aptamer is a segment of oligonucleotide and is often used to capture tumor markers because of its good designability and excellent specificity. Considering the merits of MOF and aptamer, electrochemical aptamer biosensor has been widely applied to the detection of cancer tumor markers with low concentration under complex physiological environment. This review covers the remarkable developments in MOF-based electrochemical aptasensors for the detection of tumor markers, including monometallic MOFs, bimetallic organic frameworks and calcined MOFs. And their construction strategy of electrochemical sensor was analyzed for meeting the requirements of selectivity and sensitivity. Finally, we also discussed the future perspectives for development and application of electrochemical aptasensors.