DUNI: A Portable Smartphone-Coupled Integrating Sphere for Controlled Illumination and Reliable Colorimetric Sensing:...

Area of Science:

• Analytical Chemistry
• Instrumentation
• Spectroscopy

Background:

• Smartphones are increasingly used as low-cost analytical instruments.
• Limitations include sensor dependence, variable light sources, and environmental factors, hindering reproducibility.
• Existing methods lack controlled conditions for accurate smartphone-based measurements.

Purpose of the Study:

• To develop a portable, low-cost device (DUNI) to overcome smartphone analytical limitations.
• To enable quantitative colorimetric measurements using smartphones under controlled lighting.
• To enhance the versatility and reliability of smartphone-based chemical analysis.

Main Methods:

• Developed a 3D-printed portable device integrating an "integrating sphere" with a lighting-electronic system.
• Optimized the device by assessing optical geometry, sphere characteristics, lighting, and electronic stability.
• Applied the device to determine hydrogen peroxide and biogenic amines in synthetic samples.

Main Results:

• Achieved relative errors below 5% for analyte determination.
• Established detection limits between 3 and 6 µM for hydrogen peroxide and biogenic amines.
• Demonstrated the device's effectiveness in controlled colorimetric measurements.

Conclusions:

• The DUNI device offers a portable, versatile, and cost-effective platform for smartphone-based quantitative colorimetric analysis.
• Controlled lighting conditions significantly improve measurement reproducibility and comparability.
• The technology has potential for on-site analysis, particularly in resource-limited settings.