Title :
CMOS-Based Phase Fluorometric Oxygen Sensor System
Author :
Chodavarapu, Vamsy P. ; Shubin, Daniil O. ; Bukowski, Rachel M. ; Titus, Albert H. ; Cartwright, Alexander N. ; Bright, Frank V.
Author_Institution :
Dept. of Electr. Eng., State Univ. of New York, Buffalo, NY
Abstract :
The design and development of a phase fluorometric oxygen (O2 ) sensor system using single-chip CMOS detection and processing integrated circuit (DPIC) and sol-gel derived xerogel thin-film sensor elements is described. The sensor system determines analyte concentrations using the excited state lifetime measurements of an O2-sensitive luminophore (tris(4,7-diphenyl-1,10- phenathroline)ruthenium (II)) embedded in the xerogel matrix. A light emitting diode (LED) is used as the excitation source, and the fluorescence is detected by the DPIC using a 16times16 phototransistor array on-chip. The DPIC also consists of a current mirror, current-to-voltage converter, amplifier, bandpass filter, and phase detector. The DPIC output is a dc voltage that corresponds to the detected fluorescence phase shift. With a 14-kHz modulation frequency, the entire system including driving the LED consumes 80 mW of average power. The sensor system provides stable, reproducible, analytically reliable, and fast response (~20 s) to changes in the gaseous oxygen concentrations and establishes the viability for low cost, low power and miniaturized biochemical sensor systems
Keywords :
CMOS integrated circuits; aerogels; amplifiers; band-pass filters; convertors; gas sensors; oxygen; phase detectors; phototransistors; 14 kHz; 80 nW; CMOS phase fluorometric oxygen sensor; biochemical sensor; chemical sensor; fluorescence phase shift; phase fluorometry; phototransistor array on-chip; single-chip CMOS detection; sol-gel xerogel thin-film sensor; tris(4,7-diphenyl-1,10-phenathroline)ruthenium (II); CMOS integrated circuits; CMOS process; Fluorescence; Light emitting diodes; Oxygen; Phase detection; Power system reliability; Sensor systems; Thin film circuits; Thin film sensors; CMOS; Chemical sensor; VLSI; frequency response; lifetime sensors; oxygen sensor; phase angle; phase fluorometry; phototransistor; sensor integration; signal processing; sol-gel; wavelength response; xerogel;
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
DOI :
10.1109/TCSI.2006.888680
