On August 3rd, researchers used the photoconductive properties of spider silk to develop a sensor that can detect and measure tiny changes in the refractive index of biological solutions, including glucose and other types of sugar solutions. The new light-based sensor could be used to measure blood sugar and other biochemical analytes.
The new sensor can detect and measure sugar concentration based on refractive index. The sensor is made of silk from the giant wood spider Nephila pilipes, which is encapsulated in a biocompatible photocurable resin and then functionalized with a biocompatible gold nanolayer.
"Glucose sensors are critical for diabetic patients, but these devices are often invasive, uncomfortable and not cost-effective," said research team leader Chengyang Liu from National University in Taiwan. "Spider silk is known for its excellent optomechanical properties. We wanted to explore the real-time optical detection of various sugar concentrations using this biocompatible material." It can be used to determine the concentration of fructose, sucrose, and glucose which are based on changes in the refractive index of the solution. Spider silk is the ideal for special application because it not only transmits light as an optical fiber, but it is also very strong and elastic.
To make the sensor, the researchers harvested dragline spider silk from the giant wood spider Nephila pilipes. They wrapped silk which is just 10 microns in diameter with a biocompatible light-curable resin, and cured it to form a smooth, protective surface. This created an optical fiber structure which diameter is about 100 microns, with the spider silk as the core and resin as the cladding. Then,they added biocompatible gold nanolayers to enhance the fiber's sensing capabilities.
This process forms a wire-like structure with two ends. To make measurements,it uses an optical fiber. The researchers dipped one end into a liquid sample and connected the other end to a light source and spectrometer. This allowed the researchers to detect the refractive index and used it to determine the type of sugar and its concentration.
Post time: Sep-02-2022