Disclosed are compositions and methods for the electrochemical detection of enzymes, such as enzymes that are indicative of disease, disorders, or pathogens, such as viruses, bacteria, and fungi, or other disorders. These methods can be used in point-of-care diagnostic assays for the detection of disease, disorder, or pathogen (e.g., to identify the strain of pathogen infecting a patient in a healthcare setting). The electrochemical methods described herein can also be used to assess the susceptibility of a pathogen to an antipathogen drug. Also provided are probes suitable for use in conjunction with the methods described herein.