Long before scientists test new medicines in animals or people, they study the effects of the substances on cells growing in Petri dishes. However, a 2D layer of cells is a poor substitute for the much more complex 3D structure of tissues in organs. Now, researchers reporting in the ACS jou ... more
Biosensor 'bandage' collects and analyzes sweat
Like other biofluids, sweat contains a wealth of information about what's going on inside the body. However, collecting the fluid for analysis, usually by dripping or absorbing it from the skin's surface, can be time-consuming and messy. Now, researchers have developed a bandage-like biosensor that both collects and -- in conjunction with a smart phone -- analyzes sweat. The device, which could someday help diagnose diseases, is reported in ACS' journal Analytical Chemistry.
Compared with other biofluids such as blood, sweat has the potential to be obtained less invasively for diagnostic testing. Researchers have developed tools to collect and analyze sweat, such as temporary tattoos or microfluidic devices, but they typically require wires, electronics or sophisticated structures. Tailin Xu, Li-Ping Xu, Xueji Zhang and colleagues wanted to make a wearable biosensor resembling a bandage that samples sweat and uses a simple color-changing assay to quantify various components.
To make their device, the researchers coated a flexible polyester film with a super-hydrophobic silica suspension. They then etched microwells into the silica layer to collect perspiration. At the bottom of the wells, they placed dyes that change color with pH or concentration of chloride, glucose or calcium. The team added an adhesive backing and attached the biosensor bandage onto a volunteer's skin. When the person exercised, their perspiration collected in the microwells, and the spots changed colors. By imaging and analyzing the colors with a cell phone, the researchers determined that the sweat pH was 6.5-7.0, with a chloride concentration of about 100 mM and trace amounts of calcium and glucose. The researchers are now working on increasing the sensitivity of the device.
For decades, forensic scientists have tested strands of hair to reveal drug use or poisoning. But in recent years, reports have questioned the technique -- in particular, its ability to distinguish between the intake of a substance and external contamination of the hair. Now, researchers ha ... more
Parkinson's disease is a neurodegenerative disorder that leads to progressive brain cell death and extensive loss of motor function. Despite much research being conducted on this disease, there are no definitive diagnostic tests currently available. Now, researchers report the identificatio ... more
The products we use every day leave behind chemical footprints. Learn how and why researchers are now studying those trails. Mass spectrometry is helping researchers learn more about our interactions with the everyday chemicals we use, such as DEET, caffeine, even medications. In this episo ... more
- 1Researchers grow cells in 'paper organs'
- 2Screening proteins to expose early signs of illness
- 3Nanometre gaps can crystallise liquids
- 4Blood biopsy: New technique enables detailed genetic analysis of cancer cells
- 5Biosensor 'bandage' collects and analyzes sweat
- 6A Close Look at Lithium Batteries
- 7Early in vitro testing for adverse effects on embryos
- 8Tracking Small Things in Cells
- 9International conference in May celebrates 25th anniversary of LUM GmbH in Berlin
- 10Detecting cancer before it spreads