Optics Breathe New Life Intoxygen Sensing: Sol-gel Chemistry, Combined With Optical Fibre, Offers A Novel Approach To Measuring Dissolved Oxygen And Ph Levels With Many Promising New Applications

摘要

Advances in high-performance sensorrnmaterials and optoelectronics have enabledrnnovel optical sensors for use in a diversernarray of markets including the life sciences,rnenvironmental, food and beverage, processrncontrol, and aviation. Compared torntraditional electrochemical sensingrntechniques such as galvanic, paramagnetic,rnand fuel cell sensors, these optical sensorsrn(sometimes called "optrodes," as in opticalrnelectrodes) can be made in small,rncustomizable form factors. They also havernfaster response, provide long-termrncalibration-free stability, are chemically inert,rnand couple easily to optical fibres for remoternmeasurements. The principle of operation forrnoptrodes is to trap a target-sensitivernfluorophore or pH indicator dye in a hostrnmatrix that can then be applied to the tip of arnfibre, flat substrate, adhesive membrane, orrnother surface. Optical fibres are particularlyrnversatile because they can be made intornprobes of many sizes and shapes andrncan be jacketed for deployment in harshrnenvironments. The sensing portion of the fibrernprobe is the tip, which can be made in sizesrnfrom 50 to more than 1000 μm in diameter.