Atomically Dispersed ZnN 5 Sites Immobilized on g-C 3 N 4 Nanosheets for Ultrasensitive Selective Detection of Phenanthrene by Dual Ratiometric Fluorescence.
Binhong QuPeng LiLinlu BaiYang QuZhijun LiZiqing ZhangBing ZhengJianhui SunLiqiang JingPublished in: Advanced materials (Deerfield Beach, Fla.) (2023)
Ultrasensitively selective detection of trace polycyclic aromatic hydrocarbons (PAHs) like phenanthrene (PHE) is critical but remains challenging. Herein, atomically dispersed Zn sites on g-C 3 N 4 nanosheets (sZn-CN) are constructed by thermal polymerization of a Zn-cyanuric acid-melamine supramolecular precursor for the fluorescence detection of PHE. A high amount (1.6 wt%) of sZn is grafted in the cave of CN with one N vacancy in the form of unique Zn(II)N 5 coordination. The optimized sZn-CN achieves a wide detection range (1 ng L -1 to 5 mg L -1 ), ultralow detection limit (0.35 ng L -1 , with 5-order magnitude improvement over CN), and ultrahigh selectivity toward PHE even among typical PAHs based on the built PHE-CN dual ratiometric fluorescence method. By means of in situ Fourier transform infrared spectroscopy, time-resolved absorption and fluorescence spectroscopy, and theoretical calculations, the resulting superior detection performance is attributed to the favorable selective adsorption of PHE on as-constructed atomic Zn(II)N 5 sites via the ionic cation-π interactions (Zn δ+ C 2 δ- type), and the fluorescence quenching is dominated by the inner filter effect (IFE) from the multilayer adsorption of PHE at low concentrations, while it is done by the protruded photogenerated electron-transfer process, as well as IFE from the monolayer adsorption of PHE at ultralow concentration.
Keyphrases
- heavy metals
- energy transfer
- polycyclic aromatic hydrocarbons
- label free
- loop mediated isothermal amplification
- single molecule
- real time pcr
- quantum dots
- lymph node metastasis
- squamous cell carcinoma
- hydrogen peroxide
- high resolution
- risk assessment
- gold nanoparticles
- fluorescent probe
- highly efficient
- molecularly imprinted
- electron microscopy