We at Medgadget have been covering an increasing number of lab-on-a-chip (LOC) technologies over the last number of years. Many of these existing LOC devices consist of a microfluidic cartridge containing reagents which typically needs to be analyzed by larger bench top devices. Recently, researchers from the Korea Advanced Institute of Science and Technology have come up with an interesting low-cost concept for performing these analyses using the touchscreen of a smartphone.
The researchers’ approach takes advantage of the capacitive nature of the touchscreen. Most modern touchscreens are large arrays which store electrostatic charge across their capacitive layers. When another electrical conductor, such as a human finger, comes into contact with the screen, the electrostatic charge is disturbed and a contact point is registered. By applying a bio-sample such as blood, saliva, or even urine from a LOC cartridge to the screen, the researchers hope to register specific changes in the screen’s capacitance which is indicative of the contents of the sample. In this way an app on the phone could perform the analysis and report the results.
To date the researchers have demonstrated a proof of concept which was published in the journal Angewandte Chemie International Edition at the end of October. They demonstrated that their touch-screen analysis was capable of distinguishing between solutions containing three different concentrations of DNA sourced from the bacteria that causes chlamydia using only 10 micro-liter samples.
The technology is currently unable to detect pathogens, but the ability to distinguish between sample concentrations would appear to be a significant first step. Of course a number of issues exist, namely the need to apply the sample to your phone’s screen. For the moment however, we think we’ll stick with more conventional sampling methods.
Abstract in Angewandte Chemie International Edition: A Touchscreen as a Biomolecule Detection Platform
