Unusual sequence length-dependent gold nanoparticles aggregation of the ssDNA sticky end and its application for enzyme-free and signal amplified colorimetric DNA detection

• DOI: 10.1038/srep30878
• Publication Date: 2016-08-01T09:46:48Z
• Authors: Hongfei He; Jianyuan Dai; Zhijuan Duan; Baozhan Zheng; Yan Meng; Yong Guo; Dan Xiao
• Keywords: Sequence (biology)

It is known that the adsorption of short single-stranded DNA (ssDNA) on unmodified gold nanoparticles (AuNPs) much faster than for long ssDNA, and thus leads to length-dependent AuNPs aggregation after addition salt, color solutions sequentially changed from red blue in accordance with increase ssDNA length. However, we found herein sticky end hairpin exhibited a completely different behavior compared an inverse blue-to-red variation was observed colloid solution length when within certain range. This unusual sequence might be ascribed effect stem DNA. On basis this unique phenomenon catalytic assembly (CHA) based signal amplification, novel AuNPs-based colorimetric assay picomolar sensitivity specificity developed. introduces new direction assays.