Controllable and robust dual-emissive quantum dot nanohybrids as inner filter-based ratiometric probes for visualizable melamine detection. Issue 7 (11th February 2020)

• Record Type: Journal Article
• Authors: Wang, Jing; Liu, Xinyue; Huang, Liang; Jin, Jiening; Jiang, Chenxing; Li, Daquan; Wen, Huimin; Hu, Jun
• Is Part Of: Nanoscale. Volume 12:Issue 7(2020)
• Page Start: 4562
• Page End: 4572
• Publication Date: 2020-02-11
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c9nr08849k
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : A reliable ratiometric nanoprobe with two reversible fluorescent signal changes has been constructed for high-sensitivity visual melamine quantification. Abstract : The ratiometric fluorescence technique is of great interest due to its visualization characteristics. The construction of a reliable fluorescent ratiometric nanoprobe for high-sensitivity visual quantification is highly sought after but it is limited by poor stability and controllability. Herein, we report a robust dual-emissive quantum dot nanohybrid with precise color tunability and demonstrate its potential as a two-signal-change ratiometric probe for visual detection. A novel assembly strategy was developed for spatially implanting hydrophobic green and red quantum dots (QDs) into a silica scaffold to form a dual-emissive hierarchical fluorescent silica nanohybrid. The fluorescence intensity ratio and color of the nanohybrid were precisely tailored by altering the amounts of green and red QDs. Particularly, after the alkylsilane-mediated phase transfer and exterior silica shell growth, the nanohybrid exhibited the well-preserved fluorescence features of the original QDs and robust optical/colloid stability. An inner filter-based ratiometric nanoprobe for the visual determination of melamine was ultimately devised by combining the spectra-overlapped two-colored fluorescent nanohybrid with analyte-specific gold nanoparticles. Furthermore, based on the reversible fluorescence signal changes in two-colored QDs induced by melamine, a logic gate strategy for melamine monitoring was constructed. The newly developed fluorescent ratiometric nanoprobe shows great prospects for the visual and quantitative determination of analytes in a complex biological matrix.