Gold nanoparticle based colorimetric assay of telomerase activity using the cyclic strand displacement reaction

Abstract

In this work, a novel colorimetric method for the detection of telomerase activity is proposed based on the cyclic strand displacement reaction. Target telomerase firstly generates an extension product, which displaces a single-stranded DNA from a partial DNA duplex. The released DNA probe further hybridizes with another DNA probe and initiates the cyclic strand displacement reaction coupling two hairpin DNA probes. The consumption of these DNA probes destroys the protection of gold nanoparticles (AuNPs) from salt-induced aggregation. By observing the color or measuring the UV-vis adsorption spectra, the level of telomerase activity can be evaluated. This method exhibits good sensitivity and provides a new method for telomerase assay for early diagnosis of cancers.