Nanozymes in electrochemical affinity biosensing

Over the past decade, artificial nanomaterials that exhibit properties similar to those of enzymes are gaining attraction in electrochemical biosensing as highly stable and low-cost alternatives to enzymes. This review article discusses the main features of the various nanomaterials (metal oxide, metal, and carbon-based materials) explored so far to mimic different kinds of enzymes. The unprecedented opportunities imparted by these functional nanomaterials or their nanohybrids, mostly providing peroxidase-like activity, in electrochemical affinity biosensing are critically discussed mainly in connection with their use as catalytic labels or electrode surface modifiers by highlighting representative strategies reported in the past 5 years with application in the food, environmental, and biomedical fields. Apart from outlining the pros and cons of nanomaterial-based enzyme mimetics arising from the impressive development they have experienced over the last few years, current challenges and future directions for achieving their widespread use and exploiting their full potential in the development of electrochemical biosensors are discussed.