Latest News
Web Date: January 31, 2007

Low-Cost Diagnostics On A Piece Of Paper

Millimeter-sized channels patterned on chromatography paper are the basis of an inexpensive bioassay technique
Department: Science & Technology
NO FRILLS
Patterned paper bioassay detects glucose in the left well (brown) and protein in the right well (blue).
Credit: Andres Martinez
8506sciconwhitesides
 
NO FRILLS
Patterned paper bioassay detects glucose in the left well (brown) and protein in the right well (blue).
Credit: Andres Martinez

Many clinical diagnostic methods are too complicated and too expensive to be used widely in developing countries. George M. Whitesides and his coworkers at Harvard University have thus come up with a practical method for making low-cost, portable, and simple multiplexed bioassays out of paper (Angew. Chem. Int. Ed., DOI: 10.1002/anie.200603817).

Their photolithography technique involves soaking chromatography paper in photoresist, using a mask and ultraviolet light to create a millimeter-sized channel and wells, and adding reagents for detecting multiple biological analytes.

The researchers made a glucose assay in one well based on the enzymatic oxidation of iodide to iodine with an accompanying color change from clear to brown. In a different well, they detect a protein on the basis of the color change of tetrabromophenol blue from yellow to blue when it binds the protein. The sample fluid fills the channel within a minute, and then more than 10 minutes are required for the colors to develop fully. The bioassay paper can detect clinically relevant concentrations of glucose and protein, the researchers report.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society

Leave A Comment

*Required to comment