An electrochemical probe for in-vivo measurement of H2O2 oxidation within a living tissue. The electrochemical probe includes a sensing part and a handle. The sensing part includes a working electrode including a first biocompatible conductive needle, a counter electrode including a second biocompatible conductive needle, and a reference electrode including a third biocompatible conductive needle. The working electrode, the counter electrode, and the reference electrode are configured to put in contact with the living tissue by inserting the sensing part into the living tissue. The handle includes an insertion part that may be configured to insert the sensing part into the living tissue. The sensing part is attached to the insertion part.