Highly Sensitive DNA Sensor Based on Upconversion Nanoparticles and Graphene Oxide

作者：Alonso Cristobal P; Vilela P; El Sagheer A; Lopez Cabarcos E; Brown T; Muskens O L; Rubio Retama J^*; Kanaras A G

来源：ACS Applied Materials & Interfaces, 2015, 7(23): 12422-12429.

DOI：10.1021/am507591u

• upconversion nanoparticles
• graphene oxide
• FRET
• DNA biosensor

In this work we demonstrate a DNA biosensor based on fluorescence resonance energy transfer (FRET) between NaYF4:Yb,Er nanoparticles and graphene oxide (GO). Monodisperse NaYF4:Yb,Er nanoparticles with a mean diameter of 29.1 +/- 2.2 nm were synthesized and coated with a SiO2 shell of 11 nm, which allowed the attachment of single strands of DNA. When these DNA-functionalized NaYF4:Yb,Er@SiO2 nanoparticles were in the proximity of the GO surface, the pi-pi stacking interaction between the nucleobases of the DNA and the sp(2) carbons of the GO induced a FRET fluorescence quenching due to the overlap of the fluorescence emission of the NaYF4:Yb,Er@SiO2 and the absorption spectrum of GO. By contrast, in the presence of the complementary DNA strands, the hybridization leads to double-stranded DNA that does not interact with the GO surface, and thus the NaYF4:Yb,Er@SiO2 nanoparticles remain unquenched and fluorescent. The high sensitivity and specificity of this sensor introduces a new method for the detection of DNA with a detection limit of 5 pM.

• 出版日期2015-6-17