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

Molla R Islam; Michael J Serpe

doi:10.1016/j.aca.2014.06.038

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

Anal Chim Acta. 2014 Sep 16:843:83-8. doi: 10.1016/j.aca.2014.06.038. Epub 2014 Jun 23.

Authors

Molla R Islam¹, Michael J Serpe²

Affiliations

¹ Department of Chemistry, University of Alberta, Edmonton, AB, Canada.
² Department of Chemistry, University of Alberta, Edmonton, AB, Canada. Electronic address: michael.serpe@ualberta.ca.

PMID: 25150699
DOI: 10.1016/j.aca.2014.06.038

Abstract

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.

Keywords: DNA detection; Photonic materials; Poly(N-isopropylacrylamide) based microgel; Responsive polymers.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biosensing Techniques / methods*
Colorimetry / methods
DNA / analysis*
Magnetics / methods
Pharmaceutical Solutions / chemistry*

Substances

Pharmaceutical Solutions
DNA