Biofluids provide information about the processes that happen inside the body and one of these is sweat. Sample collection of biofluids through absorption or dripping from the surface of the could be challenging. Researchers from China and US universities have innovated a biosensor that work as bandages to collect and analyze sweat.  The recent findings were published in ACS' journal Analytical Chemistry The researchers believe the device can can help in the detection of diseases. 

Collection of sweat for analysis is less invasive compared with other biofluids. Current methods in collecting and analyzing sweat involves microfluidic devices or temporary tattoos. However, these need sophisticated structures, electronics, and wires. The team led by Tailin Xu from the University of Science and Technology Beijing and his colleagues desired to make a wearable bandage-like biosensor that collects sweat and uses a simple color-changing assay to quantify different components. 

The device was created by using a super-hydrophobic silica suspension to coat a flexible polyester film. Silica layers were designed to have microwells to serve as collecting agents of sweat. The wells were color changing dyes that change with with concentration of chloride, glucose, or calcium and with pH. The device was tested on the skin of volunteers by attaching a biosensor bandage through an adhesive backing. The microwells collected the sweat when a person exercises with corresponding color changes on the spots. The camera of the phone was used to image and analyze the colors and were able to  determine the sweat pH and concentration of chloride, glucose, and calcium. The team plans to improve the sensitivity of the device.