Construction of a fast, inexpensive rapid-scanning diode-array detector and spectrometer

Area of Science:

• Spectroscopy
• Analytical Chemistry
• Biochemistry

Background:

• Rapid kinetic studies require high-speed spectroscopic detection systems.
• Existing systems may be costly or lack sufficient speed for certain applications.
• The reaction between horseradish peroxidase (HRP) and hydrogen peroxide (H2O2) is a fundamental enzymatic process often studied kinetically.

Purpose of the Study:

• To construct and characterize a novel, high-speed diode-array spectroscopic detection system.
• To demonstrate the system's capability for real-time kinetic analysis.
• To apply the system to investigate the HRP-H2O2 reaction.

Main Methods:

• A 512-element silicon photodiode-array sensor was utilized.
• The system incorporated Hamamatsu driver/amplifier and clock generator boards.
• A DRA Laboratories 12-bit, 160-kHz analog-to-digital converter was integrated.
• An IBM XT microcomputer controlled the system.
• Home-built detector housing and control/interface circuitry were detailed.

Main Results:

• The spectroscopic system achieved a scan rate of 102.9 kHz with 512 elements.
• Faster scan rates up to 128 kHz were possible with fewer diode elements.
• The system demonstrated effective real-time data acquisition for kinetic studies.
• The system was successfully applied to study the HRP-H2O2 reaction.

Conclusions:

• A cost-effective (approx. $3500) and high-speed diode-array spectroscopic detection system was successfully constructed.
• The developed system is suitable for rapid kinetic measurements in chemical and biochemical studies.
• The system provides a valuable tool for investigating fast reactions like that of HRP with H2O2.