Sensitive, simultaneous quantitation of two unlabeled DNA targets using a magnetic nanoparticle-enzyme sandwich assay.

ABSTRACT: We report herein the development of a simple, sensitive colorimetric magnetic nanoparticle (MNP)-enzyme-based DNA sandwich assay that is suitable for simultaneous, label-free quantitation of two DNA targets down to 50 fM level. It can also effectively discriminate single-nucleotide polymorphisms (SNPs) in genes associated with human cancers (KRAS codon 12/13 SNPs). This assay uses a pair of specific DNA probes, one being covalently conjugated to an MNP for target capture and the other being linked to an enzyme for signal amplification, to sandwich a DNA target, allowing for convenient magnetic separation and subsequent efficient enzymatic signal amplification for high sensitivity. Careful optimization of the MNP surfaces and assay conditions greatly reduced the background, allowing for sen

SUBMITTER: Zhang Y 

PROVIDER: S-EPMC3789254 | biostudies-literature | 2013 Oct

REPOSITORIES: biostudies-literature