AuNPs colorimetric sensor for detecting platelet-derived growth factor-BB based on isothermal target-triggering strand displacement amplification

We developed a colorimetric sensor based on gold nanoparticle (AuNP) labels and target-triggered strand displacement amplification (SDA) for the detection of platelet-derived growth factor-BB (PDGF-BB). Upon the target binding, the linear probe conformation was converted into a triple-helix conformation and then a large number of reporter oligonucleotides were produced by SDA. PDGF-BB was then determined by detecting the reporter oligonucleotides using gold nanoparticle labels. The signal output showed a linear relationship for PDGF-BB within the concentration range from 2.0 to 80 nM with a detection limit of 1.1 nM under the optimal conditions. An obvious AuNPs color change was provided when the concentration of PDGF-BB was as low as 4.0 nM. Notably, the assay demonstrated here was free from the interference of other proteins commonly existing in the human breast cancer tissue extracts. (C) 2014 Elsevier B.V. All rights reserved.