An array of highly selective Fabry–Perot optical channels for biological fluid analysis by optical absorption using a white light source for illumination

Abstract

This paper describes a laboratory microsystem (Microlab) used to measure the concentration of biomolecules in biological fluids. Rather than just one measurement channel, it comprises 16 optical channels that enable the measurement of the concentration of 16 different biomolecules with the same device. An array of 16 optical filters based on Fabry–Perot thin-film optical resonators has been designed. Each optical channel is sensitive in a single wavelength with a FWHM less than 6 nm and with a peak intensity higher than 86%. The 16 optical channel array fabrication requires only four masks, used with different deposition time. The Microlab can easily be tuned during fabrication to analyse different biomolecules only by adjusting the deposition times without affecting the device layout. A commercially available passband optical filter with a passband wavelength in the range 450–650 nm is used. Th eM icrolab requires only a white light source for illumination due to the use of selective optical filters. The quantitative measurement of uric acid in urine is demonstrated. Such a device is extremely suitable for clinical diagnosis application in clinical laboratories and at a patient’s home because of its small size, low cost and portability.