An electrochemical sensing system includes a working electrode and a reference electrode, which can at least partially be disposed in a housing. At least a portion of the working electrode includes rhodium metal. An electrical circuit is disposed in the housing and configured to be electronically coupled to the electrodes. The electrical circuit is operative to: (a) bias the working electrode at a voltage of less than about 0.4 V, and (b) measure a current corresponding to the concentration of the target analyte. A communications module is electrically coupled to the electrical circuit and configured to display a concentration of the target analyte, and/or communicate data between the electrical circuit and an external device. The electrodes are movable between a first configuration in which the electrodes are substantially disposed inside the housing, and a second configuration in which at least a portion of the electrodes is disposed outside the housing.
