title: Highly Sensitive DNA Sensor Based on Upconversion Nanoparticles and Graphene Oxide.
abstract: 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 π-π 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.
authors.affiliation: †Department of Physical Chemistry II, Faculty of Pharmacy, Complutense University of Madrid, 28040 Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Alonso-Cristobal
authors.affiliation: §Institute for Life Sciences, Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: P
authors.initials: P
authors.lastname: Vilela
authors.affiliation: ‡Department of Chemistry, University of OxfordChemistry Research Laboratory, Oxford OX1 3TA, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: El-Sagheer
authors.affiliation: †Department of Physical Chemistry II, Faculty of Pharmacy, Complutense University of Madrid, 28040 Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Lopez-Cabarcos
authors.affiliation: ‡Department of Chemistry, University of OxfordChemistry Research Laboratory, Oxford OX1 3TA, United Kingdom.
authors.forename: T
authors.initials: T
authors.lastname: Brown
authors.affiliation: §Institute for Life Sciences, Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: O L
authors.initials: OL
authors.lastname: Muskens
authors.affiliation: †Department of Physical Chemistry II, Faculty of Pharmacy, Complutense University of Madrid, 28040 Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Rubio-Retama
authors.affiliation: §Institute for Life Sciences, Physics and Astronomy, Faculty of Physical Sciences and Engineering, University of Southampton, Southampton SO17 1BJ, United Kingdom.
authors.forename: A G
authors.initials: AG
authors.lastname: Kanaras
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004277:DNA, Single-Stranded / Q000032:analysis*; D004871:Erbium; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005459:Fluorides; D006108:Graphite / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D015018:Ytterbium; D015019:Yttrium
chemical_list: D004277:DNA, Single-Stranded; D010087:Oxides; C525362:sodium yttriumtetrafluoride; D015019:Yttrium; D006108:Graphite; D004871:Erbium; D015018:Ytterbium; D005459:Fluorides
keywords: DNA biosensor; FRET; graphene oxide; upconversion nanoparticles