Electrochemical vs. Photometric Detection

The evolution of diabetic test strips is defined by the transition from Photometric to Electrochemical detection.

Photometric technology, dominant in early generations, relies on an enzymatic reaction producing a color change on a strip, which is read by a reflectometer. While foundational, it suffered from high sample volume requirements (>3µL), susceptibility to optical interference (dirt, ambient light), and slower reaction times.

Electrochemical technology, the modern standard, utilizes biosensors where glucose oxidation generates an electrical current (Amperometry) or total charge (Coulometry). This method employs mediators (e.g., ferricyanide) to shuttle electrons to an electrode, bypassing the need for oxygen. Key advantages include:

• Minimal Sample Size: 0.3–1.0 µL via capillary action.
• Speed: Results in under 5 seconds.
• Robustness: Elimination of optical maintenance and reduced interference from ambient factors.

Currently, electrochemical sensors manufactured via screen-printing or laser ablation dominate the SMBG market due to superior user experience and manufacturing scalability.