前往化源商城

Lab on a Chip 2018-04-05

“Dip-and-read” paper-based analytical devices using distance-based detection with colour screening

Kentaro Yamada, Daniel Citterio, Charles Henry

文献索引:10.1039/C8LC00168E

全文:HTML全文

摘要

An improved microfluidic paper-based analytical device (PAD) using colour screening to enhance device performance is described. Current detection methods for PADs relying on the distance-based signaling motif can be slow due to the assay time being limited by capillary flow rates that wick fluid through the detection zone. For traditional distance-based detection motifs, analysis can take up to 45 min for a channel length of 5 cm. By using a colour screening method, quantitation using distance-based PAD can be achieved in minutes using a “dip-and-read” approach. A colorimetric indicator line deposited onto a paper substrate using inkjet-printing undergoes a concentration-dependent colorimetric response for a given analyte. This colour intensity-based response has been converted to a distance-based signal by overlaying a colour filter with a continuous colour intensity gradient matching the colour of the developed indicator line. As a proof-of-concept, Ni quantification in welding fume was performed as a model assay. The results of multiple independent user testing gave the mean absolute percentage error and average relative standard deviations of 10.5% and 11.2% respectively, which were an improvement upon analysis based on simple visual colour comparison with a read guide (12.2%, 14.9%). In addition to the analytical performance comparison, an interference study and a shelf life investigation were performed to further demonstrate practical utility. The developed system demonstrates an alternative detection approach for distance-based PADs enabling fast (~ 10 min), quantitative, and straightforward assays.