Electrochemical Point Of Care Detection Method Based On Smartphone

Point-of-care testing (POCT) plays a more and more important role in biomedical diagnosis worldwide with the rapid development of medical technology. As a detecting technology with miniaturized experimental instrument, simple operation method and instant test results, it not only shortens the time of diagnosis, but also reduces social health care costs. The ability to function normally in understaffed or unstable power source situation makes it more appealing for developing countries and some remote areas. Herein, we developed an electrochemical detection method based on sensing chip connected to smartphone through potentiometric reader, the detailed works are as follows:We developed a system comprised of a sensing chip, a smartphone with customized APP and a potentiometric reader for electrochemical detection. For demonstration, we employed the sensing chip to detect glucose with a limit of detection (LOD) of 0.07 mM and a coverage of 1.9-30 mM. A production flow was sorted out for chip batch production, including carbon electrode printing, silver ink spotting, siphon channel laser engraving, hydrophilic treating, layers assembling, chip cutting and reagents drying.Plastic sensing chip was combined with smartphone equipped with specially designed APP to electrochemically detect a-amylase within 5-35℃. For the demonstration, a calibration curve with a limit of detection (LOD) of 0.12 U/mL(20 ℃) and a coverage of 30-1000 U/mL is established. To further prove the practical applicability, real saliva sample taken from volunteer before and after specific events and exposure to effective picture meant to induce emotion fluctuation are freshly detected without pretreatment, the results gained within 5 minutes show great consistency with psychological research.A novel paper-based acetylcholinesterase(AChE) potentiometric biosensor patterned with concentration cell is developed and examined for pesticide detection using smartphone. Parameters including mediator, substrate and enzyme concentration as well as patterned feature gained through wax printing were optimized and 3D printing device for signal obtainment and transmission was designed and fabricated via 3D printer. For the demonstration, a calibration curve of pesticide with a limit of detection (LOD) of 0.22 ppm is established.