Simple, distance-based measurement for paper analytical devices.

Title	Simple, distance-based measurement for paper analytical devices.
Authors	Owen S. Henry, John Volckens, Andrew C Cunningham, David M. Cate, Wijitar Dungchai
Magazine	Lab on a Chip
Date	06/21/2013
DOI	10.1039/c3lc50072a
Introduction	Paper-based analytical devices (PADs) are an emerging class of cost-effective chemical sensor technologies for point-of-use applications. Traditional PADs often require instrumentation such as cameras for quantitative detection. This study introduces a simplified method that enhances PAD quantitative measurement by utilising the colour development distance as a detection motif. The technique, known as distance-based detection, enables PAD chemistries to be more portable and resource-efficient, eliminating the need for peripheral equipment. The method's utility is demonstrated through glucose, nickel, and glutathione measurements using enzymatic reactions, metal complexation, and nanoparticle aggregation, respectively. Results show a strong quantitative correlation with certified standards in complex sample matrices. This research is the first to showcase distance-based PAD detection as an affordable and versatile sensor technology for point-of-use applications.
Quote	Owen S. Henry, John Volckens and Andrew C Cunningham et al. Simple, distance-based measurement for paper analytical devices.. 2013. DOI: 10.1039/c3lc50072a
Element	Nickel (Ni)