Researchers have developed a sensor with spider silk that can detect and measure small changes in the refractive index of a biological solution.
Researchers have harnessed spider silk from Nephila pilipes which is 10 microns in diameter. The spider silk is This silk is spun into a 100 micron diameter optic fiber along with a biocompatible resin. It is combined with a photocurable resin to form a protective surface. Then      a thin biocompatible layer of nano-gold is added to enhance the ability of sensation. The researchers immersed one end in the liquid sample and the other end to the light source and spectrometer. This enables the researchers to detect the refractive index and to determine the sugar type and the concentration.
The sensor is tested with different sugar solutions with different concentrations at room temperature. The measurements were repeated 10 times at intervals of 5 minutes. The performance of the sensor is determined by comparing the light intensity spectra acquired with commercial refractometer. The sensor was successfully able to identify both the type of sugar and its concentration level. The new light-based sensor is believed to be used in measuring blood sugar and other biochemical analytes.
The accuracy and the stability of it under different environmental changes should be tested before used for real-time usage in clinics. The team is also working on developing software to enable the sensor to be used in mobile devices for card readings. They also try to extend the functionality to be able to measure different biochemical components in human blood. This also includes lactose and fat.
“The measurement precision and sensing sensitivity we achieved suggests that the sensor can accurately estimate the concentration of an unknown sugar solution,” said research team leader Cheng-Yang Liu from National Yang Ming Chiao Tung University in Taiwan.
