At the Hong Kong Polytechnic University and Zhejiang University in China, researchers have developed a highly sensitive glucometer integrated inside an opto-microfluidic device. Electrochemical sensors can be used instead of optical components, but they’re subject to interference and can produce inconsistent results. The new sensor can detect glucose oxidase at concentrations below 1 nM (10-9 molarity).
The researchers believe that such impressive sensitivity may allow the development of small devices that stick to the skin and measure glucose from sweat.
Some of the details according to the study abstract in Biomedical Optics Express:
A long-period grating (LPG) inscribed in a small-diameter single-mode fiber (SDSMF) is employed as an optical refractive-index (RI) sensor. With the layer-by-layer (LbL) self-assembly technique, poly (ethylenimine) (PEI) and poly (acrylic acid) (PAA) multilayer film is deposited on the SDSMF-LPG sensor for both supporting and signal enhancement, and then a glucose oxidase (GOD) layer is immobilized on the outer layer for glucose sensing. A microfluidic chip for glucose detection is fabricated after embedding the SDSMF-LPG biosensor into the microchannel of the chip. Experimental results reveal that the SDSMF-LPG biosensor based on such a hybrid sensing film can ultrasensitively detect glucose concentration as low as 1 nM. After integration into the microfluidic chip, the detection range of the sensor is extended from 2 µM to 10 µM, and the response time is remarkablely shortened from 6 minutes to 70 seconds.
Study in Biomedical Optics Express: Optical fiber LPG biosensor integrated microfluidic chip for ultrasensitive glucose detection…
Via: Optical Society…