Electrochemical sensors for analyte detection in water and reference correction method

A voltammetric sensor system comprising:

• a sensor comprising a working electrode, a counter electrode, and a reference electrode;
• and
• an electronic system connected to the working electrode, the counter electrode, and the reference electrode and being configured to:
• apply a voltage difference between the working electrode and the reference electrode;
• and
• conduct a square wave voltammetric scan over at least a portion of an electrochemical window extending from a start scan value to an end scan value using the working electrode, the counter electrode, and the reference electrode,
• wherein the electronic system further comprises a dynamic electrochemical window calculator configured to change the end scan value of the electrochemical window to account for drift in the reference electrode,
• wherein:
• the dynamic electrochemical window calculator is configured to store the start scan value, the end scan value, a baseline current value for current between the working electrode and the counter electrode, a threshold current value for current between the working electrode and the counter electrode that is offset above the baseline current value, and a voltage of significance value that is between the start scan value and the end scan value;
• the electronic system is configured to conduct the square wave voltammetric scan starting at the start scan value and progressing in square wave steps to the voltage of significance value and then from the voltage of significance value toward the end scan value;
• and
• the dynamic electrochemical window calculator:
• is configured to monitor current between the working electrode and the counter electrode as the square wave voltammetric scan progresses from the voltage of significance value toward the end scan value to determine if said current between the working electrode and the counter electrode exceeds the threshold current value;
• and
• comprises a current limiter that interrupts the square wave voltammetric scan before the square wave voltammetric scan reaches the end scan value to limit oxidation of the working electrode if said current between the working electrode and the counter electrode exceeds the threshold current value after the square wave voltammetric scan has progressed to the voltage of significance value.