A highly sensitive biosensing platform based on upconversion nanoparticles and graphene quantum dots for the detection of Ag+. (5th May 2017)

• Record Type: Journal Article
• Authors: He, Lu; Yang, Lin; Zhu, Hao; Dong, Wenkui; Ding, Yujie; Zhu, Jun-Jie
• Is Part Of: Methods and applications in fluorescence. Volume 5:Number 2(2017:Jun.)
• Publication Date: 2017-05-05
• Subjects: upconversion nanoparticles -- graphene quantum dots -- biosensors -- silver ions; Fluorescence spectroscopy -- Periodicals; Fluorescence -- Periodicals; Spectrometry, Fluorescence -- Periodicals; Fluorescence -- Periodicals; Fluorescence; Fluorescence spectroscopy; Periodicals; 535.352
• DOI: 10.1088/2050-6120/aa6e0d
• Languages: English
• ISSNs: 2050-6120

Abstract

Abstract: A novel luminescence 'Turn-On' nanoplatform for the sensitive sensing of Ag + was fabricated based on luminescence resonance energy transfer technique between sodium citrate functionalized upconversion nanoparticles (Cit-UCNPs, energy donor) and graphene quantum dots (GQDs, energy acceptor). Amino-labeled single-stranded DNA (NH2 -ssDNA) containing a number of cytosine (C) was conjugated on the surface of the Cit-UCNPs to capture Ag + ions. Due to the π – π stacking interaction between NH2 -ssDNA and GQDs, the upconversion luminescence can be quenched. However, upon the addition of Ag +, the π – π stacking interaction weakens due to the formation of the hairpin structure of C–Ag + –C on the UCNPs. As a result, GQDs will leave the surface of the UCNPs and the upconversion luminescence can be enhanced (Turn-On). Based on this fact, the sensor was developed for the detection of Ag + with a linear concentration range from 2 × 10 −4 to 1 μ M and a detection limit as low as 60 pM. The assay method is fairly simple with high selectivity and sensitivity, which can be used for the determination of Ag + in environmental water samples.