Sensitive optical bio-sensing of p-type WSe2 hybridized with fluorescent dye attached DNA by doping and de-doping effects

Nanotechnology. 2017 Oct 27;28(43):435501. doi: 10.1088/1361-6528/aa8889. Epub 2017 Aug 25.

Abstract

Layered transition metal dichalcogenides, such as MoS2, WSe2 and WS2, are exciting two-dimensional (2D) materials because they possess tunable optical and electrical properties that depend on the number of layers. In this study, the nanoscale photoluminescence (PL) characteristics of the p-type WSe2 monolayer, and WSe2 layers hybridized with the fluorescent dye Cy3 attached to probe-DNA (Cy3/p-DNA), have been investigated as a function of the concentration of Cy3/DNA by using high-resolution laser confocal microscopy. With increasing concentration of Cy3/p-DNA, the measured PL intensity decreases and its peak is red-shifted, suggesting that the WSe2 layer has been p-type doped with Cy3/p-DNA. Then, the PL intensity of the WSe2/Cy3/p-DNA hybrid system increases and the peak is blue-shifted through hybridization with relatively small amounts of target-DNA (t-DNA) (50-100 nM). This effect originates from charge and energy transfer from the Cy3/DNA to the WSe2. For t-DNA detection, our systems using p-type WSe2 have the merit in terms of the increase of PL intensity. The p-type WSe2 monolayers can be a promising nanoscale 2D material for sensitive optical bio-sensing based on the doping and de-doping responses to biomaterials.

MeSH terms

  • Base Pairing
  • Biosensing Techniques*
  • Carbocyanines / chemistry
  • DNA / analysis*
  • DNA / chemistry
  • DNA Probes / chemistry
  • Energy Transfer
  • Fluorescent Dyes / chemistry
  • Luminescence
  • Luminescent Measurements / methods*
  • Nucleic Acid Hybridization
  • Optical Devices*
  • Selenium Compounds / chemistry*
  • Tungsten Compounds / chemistry*

Substances

  • Carbocyanines
  • DNA Probes
  • Fluorescent Dyes
  • Selenium Compounds
  • Tungsten Compounds
  • cyanine dye 3
  • DNA