What does an electrochemical sensor use to detect a substance?

What does an electrochemical sensor use to detect a substance?

• A. Accelerator
• B. Enzyme
• C. Reagent
• D. Catalyst

Answer: (C)

An electrochemical sensor detects a substance by relying on a chemical species that participates in a redox reaction at the electrode. When the target is present, this reagent (often a mediator) engages in electron transfer, producing a current that the sensor reads. The size of that current corresponds to how much of the substance is there. Enzymes are used in some biosensors to provide specificity by transforming the analyte into an electroactive form, but the actual signal comes from the chemical reaction involving the reagent. Accelerators or catalysts can influence reaction speed, but they don’t by themselves generate the detectable electrical signal in the same direct way. So the component responsible for detecting the substance in this type of sensor is the reagent.

An electrochemical sensor detects a substance by relying on a chemical species that participates in a redox reaction at the electrode. When the target is present, this reagent (often a mediator) engages in electron transfer, producing a current that the sensor reads. The size of that current corresponds to how much of the substance is there.

Enzymes are used in some biosensors to provide specificity by transforming the analyte into an electroactive form, but the actual signal comes from the chemical reaction involving the reagent. Accelerators or catalysts can influence reaction speed, but they don’t by themselves generate the detectable electrical signal in the same direct way. So the component responsible for detecting the substance in this type of sensor is the reagent.