A light detection cell to be used in a micro analysis system for ammonia

Area of Science:

• Microfluidics
• Analytical Chemistry
• Materials Science

Background:

• Micro total analysis systems (µTAS) require miniaturized detection components.
• Accurate quantification of chemical species at low concentrations is crucial for µTAS applications.
• Indophenol blue is a key analyte in specific chemical analyses.

Purpose of the Study:

• To design and fabricate a micromachined light detection cell for µTAS.
• To enable sensitive and reproducible measurements of indophenol blue.
• To characterize the performance of the developed light detection cell.

Main Methods:

• Micromachining of silicon using potassium hydroxide/isopropyl alcohol (KOH/IPA) etching.
• Fabrication of a light detection cell with sub-microliter internal volume.
• Spectrophotometric measurement of indophenol blue concentrations.

Main Results:

• A functional light detection cell with a volume < 1 µL was successfully realized.
• The cell demonstrated good reproducibility for indophenol blue measurements across a concentration range of 0.02 to 50 µM.
• KOH/IPA etching produced 45° sidewalls suitable for optical coupling.

Conclusions:

• The developed micromachined light detection cell is suitable for miniaturized analytical systems.
• The cell offers high sensitivity and reproducibility for indophenol blue detection.
• This technology advances the capabilities of microfluidic chemical analysis.