Signal amplification on a DNA-tile-based biosensor with enhanced sensitivity

Herein, we report our work to improve the detection sensitivity of a DNA-tile-based and self-assembled biosensing platform. This was achieved using hybridization chain reaction (HCR) as a signal amplifier on a water-soluble self-assembled DNA nanoarray carrying detection probes.

The fluorescence enhancement on the addition of specific detection targets was observed directly by confocal fluorescence microscopy.

The versatility of the system was demonstrated by successful detection of SARS viral DNA and ATP. Improvement of sensitivity by two orders of magnitude was achieved for both targets, compared with our previously reported system without signal amplification.

In summary, this work provides proof-of-concept that HCR can occur efficiently on DNA-tile-based nanoarrays, thus facilitating more sensitive detection. The merging of HCR with combinatorial encoding systems to realize highly sensitive and multiplexed biosensing may provide new tools for nanomedical applications.