Single Molecule Fluorescence Study of G-Quadruplex Sensor

Abstract

Specific detection of telomere DNA sequences in diagnostic technologies has been of considerable interest in recent years. Typically, the sequence of interest is amplified by polymerase chain reaction (PCR) and detected either simultaneously by fluorogenic oligonucleotide probes or by subsequent capture to a planar array or microparticle. We have designed a two-colour G-quadruplex Sensor using sandwich hybridisation approach1,2 and studied by Single Molecule Fluorescence. The method we used can remove the need for amplification before analysis, which would lead to more rapid, accurate methods3. In this study, the sensor combined three ssDNAs and fluorescent nanoparticle to assemble multicolour fluorescent duplex by sandwich hybridisation. We have investigated the structure and unfolding kinetics of the telomeric intramolecular G quadruplex by using fluorescence resonance energy transfer. The result demonstrates that the proposed sandwich G-quadruplex sensor could be used as an easy-use, high sensitive and cheaper approach for bio-assays.