Fourier transform infrared detection in miniaturized total analysis systems for sucrose analysis

Area of Science:

• Analytical Chemistry
• Biotechnology
• Materials Science

Background:

• Enzymatic assays are crucial for quantifying carbohydrates like sucrose.
• Developing sensitive and efficient analytical systems for real-time measurements is an ongoing challenge.
• Porous silicon offers unique properties for microreactor fabrication and enzyme immobilization.

Purpose of the Study:

• To develop and validate a novel flow system for the enzymatic determination of sucrose.
• To integrate a micromachined porous silicon reactor with a mid-infrared fiber-optic flow cell.
• To assess the system's performance for analyzing sucrose in aqueous solutions and complex matrices.

Main Methods:

• Enzymatic hydrolysis of sucrose using immobilized β-fructosidase in a porous silicon microreactor.
• Acquisition of Fourier-transform infrared (FT-IR) spectra before and after enzymatic reaction.
• Utilized a miniaturized fiber-optic flow cell with a probed volume of approximately 10 nL for mid-IR measurements.
• Fabricated porous silicon via anodization of silicon in a HF/ethanol mixture.

Main Results:

• Achieved a linear calibration curve for sucrose determination in the range of 10–100 mmol/L.
• Demonstrated successful analysis of binary sucrose/glucose mixtures without interference from glucose.
• Validated the method through the determination of sucrose in real samples.
• The system enabled sensitive detection with a small sample volume.

Conclusions:

• The developed flow system offers a sensitive and selective method for enzymatic sucrose determination.
• The integration of porous silicon microreactors and fiber-optic flow cells is effective for mid-IR spectroscopic analysis.
• This approach shows significant potential for analyzing sucrose in various applications, including food and biological samples.