2,4,6-Tris (2-pyridyl)-1,3,5-triazine nanobelts as an effective fluorescent sensing platform for DNA detection

In the present study, we report on the use of 2,4,6-tris (2-pyridyl)-1,3,5-triazine nanobelts (TPTNBs) as an effective fluorescent sensing platform for DNA detection for the first time. The general concept used in this approach is based on adsorption of fluorescently labeled single-stranded DNA (ssDNA) probe by TPTNB, due to the strong pi-pi stacking between unpaired DNA bases and TPTNB. As a result, the fluorophor is brought into close proximity of TPTNB, leading to fluorescence quenching. Upon presence of the target ssDNA, specific hybridization with the target takes place to form a double-stranded DNA (dsDNA). The resultant dsDNA cannot be adsorbed by TPTNB due to its rigid conformation and the absence of unpaired DNA bases. Thus, the fluorophor is seperated from TPTNB accompanied by fluorescence recovery. The present system shows a detection limit as low as 3 nM and has a high selectivity down to single-base mismatch.