A WS2 nanosheet-based platform for fluorescent DNA detection via PNA–DNA hybridization

Abstract

The WS₂ nanosheet, a two-dimensional layered nanomaterial, shows high fluorescence quenching ability for the dye-labeled ssDNA. Currently, most of the fluorescent DNA detection methods employ DNA as a probe for recognition of target DNA. Peptide nucleic acid (PNA) is a DNA mimic but a neutral molecule, showing superior hybridization properties to target DNA. Based on the unique properties of WS₂ nanosheet and PNA–DNA hybridization, we have developed a rapid, simple, stable and sensitive approach for DNA detection based on good fluorescence quenching ability of the WS₂ nanosheet as well as high binding affinity and specificity of PNA to DNA. This novel assay is capable of exhibiting high sensitivity and specificity with a detection limit of 500 pM, and discriminating between single bases.