Progress in enhancing the electrochemical detection performance of trace tumor markers based on catalytic reactions

Sensitive detection of tumor markers is one of the most important safeguards for early diagnosis of cancer, selection of therapeutic strategies and prognostic monitoring. The content of tumor markers in serum is low, usually existing at trace level, and even very few other tumor markers are only on the order of femtograms or picograms per millilitre of serum, and subtle changes in their concentrations are indicative of tumor occurrence, progression and therapeutic efficacy. It is of great clinical significance and has received extensive attention how to achieve sensitive detection of small concentration changes of tumor markers at trace level. Because of its high sensitivity, fast response, easy operation, and miniaturization of the instrument, electrochemical immunosensors have received much attention and made great progress in the study of detecting small concentration changes of tumor markers at trace level. This paper reviews the progress made in catalytic reactions to enhance the performance of electrochemical detection of tumor markers, with special focus on the application of bioenzymes, nano-enzymes, and the use of electrochemical metal catalysts, and also provides an outlook on the problems to be solved.