Smartphone-based paper microfluidic detection implementing a versatile quick response code conversion strategy.

The development of smartphone electronics and the prevalence of quick response (QR) codes make them valuable tools for digitizing and decentralizing tests to fields and households. Now there is a growing trend for adapting them into sensing and diagnostic needs from paper microfluidics. Herein, we show a new QR-coded microfluidic paper-based analytical device (QR-coded μPAD) consisting of stacked layers of printed QR code, transparency film, and microfluidically patterned paper. It combines multichannel colorimetric sensing with QR code generation into smartphone-based multiplexed assays with the aid of gray patterns on the transparency film. The QR-coded μPAD paired with an accompanying mobile application is successfully applied to simultaneous implementation of beverage/aquatic tests and QR code functions. Our QR code conversion strategy provides the superb flexibility and compatibility for paper microfluidics of various designs. The work suggests that our versatile integration of paper microfluidics, smartphone science, and QR code uses can make rapid, interactive, and automated on-site testing and reporting, leading to opportunities to advance the development of smart paper microfluidics. [Display omitted] • A versatile QR code conversion strategy for paper microfluidics was proposed. • Stacked layer design and printed gray patterns hold the key to device fabrication. • Simultaneous implementation of analyte analysis and QR code functions in one scan. • Our QR-coded μPADs were applied into beverage tests and water quality monitoring. [ABSTRACT FROM AUTHOR]