Core Concepts
A smartphone's compass can be used to analyze biomarkers like glucose and pH in body fluids and other liquids through a simple, low-cost sensor strip.
Abstract
The content discusses a new method developed by researchers at the National Institute of Standards and Technology (NIST) that uses a smartphone's compass to measure biomarkers in liquids. The key highlights are:
The researchers embedded a small magnet in a "smart hydrogel" strip that expands or contracts based on the concentration of the target biomarker, such as glucose or pH, in the liquid sample.
As the hydrogel strip changes size, it moves the magnet, which the smartphone's magnetometer (compass) can detect. This allows the smartphone to measure the biomarker levels.
In proof-of-concept tests, the researchers accurately measured glucose levels in alcoholic beverages and pH levels in various liquids using this method.
The technique could potentially be adapted to detect other biomarkers or molecules, and could also be used to check for chemical contaminants in water.
More testing is needed to confirm the method works with biological fluids like blood, sweat, or saliva. Challenges include potential interference from other molecules in complex fluids.
The researchers aim to develop a simple, low-cost, and disposable sensor strip that can be used with a smartphone, similar to a pool pH test strip.
Stats
The detection limit for glucose reached micromolar concentrations, on par with or better than some widely used glucose sensors.
Each pH hydrogel strip costs about 3 cents, and glucose strips cost 16 cents, with potential for lower prices in bulk.
Quotes
"We're just at this point demonstrating this new way of sensing that we hope [will be] very accessible and very portable."
"It might enable new capabilities for advanced sensing applications in field settings or even at home."