A novel label-free colorimetric assay for DNA concentration in solution.

Anal Chim Acta

Department of Chemistry, University of Alberta, Edmonton, AB, Canada. Electronic address:

Published: September 2014

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Optical devices were fabricated by sandwiching a "monolithic" poly(N-isopropylacrylamide-co-N-(3-aminopropyl) methacrylamide hydrochloride) (pNIPAm-co-APMAH) microgel layer between two semitransparent Au layers. These devices, referred to as etalons, exhibit characteristic multipeak reflectance spectra, and the position of the peaks in the spectra primarily depends on the distance between the Au surfaces mediated by the microgel layer thickness. Here, we show that the positively charged microgel layer can collapse in the presence of negatively charged single stranded DNA (ssDNA) due to ssDNA induced microgel crosslinking. The collapse results in a change in the etalon's optical properties, which can be used to detect target DNA in a complex mixture.

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http://dx.doi.org/10.1016/j.aca.2014.06.038DOI Listing

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