What does an electrochemical sensor use to detect a substance?

An electrochemical sensor detects a substance by utilizing a reagent that interacts with the target analyte. In electrochemical sensing, the reagent often participates in a chemical reaction that produces a measurable electrical signal corresponding to the concentration of the substance being detected. This could involve redox reactions where the reagent changes its oxidation state upon reacting with the analyte. The resulting change in current or voltage is then measured and translated into quantifiable data regarding the concentration of the substance.

While other options like enzymes or catalysts may play roles in different sensing mechanisms, they are not the primary components for all electrochemical sensors. Enzymes, for instance, are specific to biological sensors and would not be universally applicable. Catalysts and accelerators might influence chemical reactions but do not serve the fundamental purpose of detecting substances in the context of an electrochemical sensor, which directly relies on a specific reagent for its detection capabilities.