Sensitivity-Enhanced CMOS Phase Luminometry System Using Xerogel-Based Sensors.

Area of Science:

• Materials Science
• Electrical Engineering
• Analytical Chemistry

Background:

• Phase luminometry offers a sensitive method for analyte detection.
• Developing integrated sensor systems with tunable sensitivity is crucial for advanced monitoring.
• Xerogel thin films provide a versatile matrix for immobilizing luminescent molecules.

Purpose of the Study:

• To design and implement a phase luminometry sensor system with enhanced and tunable detection sensitivity.
• To utilize a complementary metal-oxide semiconductor (CMOS) integrated circuit for improved sensor performance.
• To demonstrate a prototype oxygen sensor for potential biomedical applications.

Main Methods:

• Employed sol-gel derived xerogel thin films for immobilizing oxygen-responsive luminescent molecules.
• Utilized phase luminometry, monitoring the phase shift of emission signals excited by a modulated sinusoidal signal.
• Integrated a custom CMOS circuit featuring a phototransistor array, signal converters, amplifier, and tunable phase shift detector.

Main Results:

• Achieved a tunable detection sensitivity of 118 mV per 1% change in oxygen concentration.
• Demonstrated a fast sensor response time on the order of seconds.
• The CMOS integrated circuit consumed an average power of 14 mW at a 5-V supply and 38-kHz modulation frequency.

Conclusions:

• The developed phase luminometry sensor system offers a novel approach for tunable and improved analyte detection sensitivity.
• The integration of CMOS technology enhances the performance and potential for miniaturization of luminometry sensors.
• This system shows promise for various biomedical monitoring applications requiring sensitive and specific analyte detection.