Sensitive Detection of ssDNA Using an LRET-Based Upconverting Nanohybrid Material

Joe Gerald Jesu Raj, Marta Quintanilla, Khaled Mahmoud, Andy Ng, Fiorenzo Vetrone, Mohammed Zourob

Research output: Contribution to journalArticle

22 Citations (Scopus)


Water-dispersible, optical hybrid nanoparticles are preferred materials for DNA biosensing due to their biocompatibility. Upconverting nanoparticles are highly desirable optical probes in sensors and bioimaging owing to their sharp emission intensity in the visible region. We herein report a highly sensitive ss-DNA detection based on an energy transfer system that uses a nanohybrid material synthesized by doping NaYF<inf>4</inf>:Tm<sup>3+</sup>/Yb<sup>3+</sup> upconverting nanoparticles (UCNPs) on silica coated polystyrene-co-acrylic acid (PSA) nanoparticles (PSA/SiO<inf>2</inf>) as the donor, and gold nanoparticles (AuNPs) decorated with Ir(III) complex as the acceptor. UCNPs tagged on PSA/SiO<inf>2</inf> and the cyclometalated Ir(III)/AuNP conjugates were then linked through the ss-DNA sequence. Sequential addition of the target DNA to the probe molecular beacon complex resulted in the separation of the optical nanohybrid material and the quencher, leading to a measurable increase in the blue fluorescence emission intensity. Our results have shown a linear relationship between the fluorescence intensity and target DNA concentration down to the picomolar. (Figure Presented).

Original languageEnglish
Pages (from-to)18257-18265
Number of pages9
JournalACS Applied Materials and Interfaces
Issue number33
Publication statusPublished - 26 Aug 2015



  • biosensing
  • energy transfer
  • luminescence
  • nanohybrid
  • upconversion

ASJC Scopus subject areas

  • Materials Science(all)

Cite this