What is the principle behind most glucose point-of-care tests?

• A. Enzymatic colorimetric
• B. Reflectance photometry
• C. Electrochemical detection
• D. Turbidimetry

Answer: (B)

Glucose point-of-care tests mainly use electrochemical detection. In these tests, glucose oxidase (or another enzyme) on the test strip catalyzes a reaction with glucose, producing electrons that flow to an electrode. The meter detects the electrical signal—typically a small current—whose magnitude is proportional to the glucose concentration in the sample. This electrical readout allows rapid, accurate results with very small sample volumes, and is robust to variations in sample color or turbidity, which is why it’s favored for portable, at-home testing.

Colorimetric approaches that rely on a color change read by reflectance can be used in some assays, but they’re more prone to interference from the sample’s color and lighting and are less common for glucose meters. Hence, the electrochemical detection principle is the standard for most glucose point-of-care tests.