Abstract: During the last forty years, enzyme-base biosensors have had great success in the detection and quantification of various biologically-relevant molecules. However, native enzymes can sometimes be costly, delicate to manipulate or simply absent for a particular analyte. Hence, artificial or synthetic enzymes could be a useful alternative to natural proteins for the conception of new biosensors, since they can be, a priori, designed in their entirety, as well as more robust, available, chemically malleable and cheap, in comparison with their natural analogues. In this Perspective, we will provide a snapshot of this emerging research field.