A ratiometric fluorescent nanosensor for the detection of silver ions using graphene quantum dots

• Published in: Sensors and actuators. B, Chemical Chemical, 2017-12, Vol.253, p.239-246
• Main Authors: Zhao, Xian-En, Lei, Cuihua, Gao, Yue, Gao, Han, Zhu, Shuyun, Yang, Xue, You, Jinmao, Wang, Hua
• Format: Article
• Language: English
• Subjects: Emissions; Energy transfer; Fluorescence; Graphene; Graphene quantum dots; Nanosensors; o-phenylenediamine; Phenylenediamine; Quantum dots; Ratiometric fluorescent nanosensor; Sensors; Silver; Silver ions; Water
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2017.06.086

A ratiometric fluorescent nanosensor has been developed for probing Ag+ ions based on the fluorescence resonance energy transfer (FRET) between graphene quantum dots (GQDs) and 2,3-diaminiophenazine (DAP) yielded from the Ag+ ions-oxidized o-phenlyenediamine (OPD). [Display omitted] •A novel ratiometric fluorescent nanosensor for Ag+ ions was established with GQDs.•The oxidase-like activity of Ag+ ions towards OPD was employed for the design of this nanosensor.•A FRET mechanism between GQDs and DAP was demonstrated.•This rationmetric fluorescent nanosensor can detect Ag+ ions in water samples. A ratiometric fluorescent nanosensor was reported for the first time for the sensitive and selective analysis of Ag+ ions by employing graphene quantum dots (GQDs) as the reference fluorophore and o-phenylenediamine (OPD) as the specific recognition probe. Upon the addition of Ag+ ions, OPD could be oxidized to produce 2,3-diaminophenazine (DAP) with a strong fluorescence emission at 557nm, whereas the fluorescence of GQDs at 445nm would be simultaneously quenched by the so generated DAP through fluorescence resonance energy transfer (FRET). A ratiometric fluorescent Ag+ nanosensor was thus developed. The fluorescence intensity ratios of DAP to GQDs linearly increased with the increasing of Ag+ concentrations in the range of 0–115.2μM, with a detection limit down to 250nM. Furthermore, the feasibility of practical applications of the developed detection strategy for probing Ag+ ions in real water samples was demonstrated.