title: Tunable Fluorescent Silica-Coated Carbon Dots: A Synergistic Effect for Enhancing the Fluorescence Sensing of Extracellular Cu²⁺ in Rat Brain.
abstract: Carbon quantum dots (CDs) combined with self-assembly strategy have created an innovative way to fabricate novel hybrids for biological analysis. This study demonstrates a new fluorescence platform with enhanced selectivity for copper ion sensing in the striatum of the rat brain following the cerebral calm/sepsis process. Here, the fabrication of silica-coated CDs probes is based on the efficient hybridization of APTES which act as a precursor of organosilane self-assembly, with CDs to form silica-coated CDs probes. The fluorescent properties including intensity, fluorescence quantum yield, excitation-independent region, and red/blue shift of the emission wavelength of the probe are tunable through reliable regulation of the ratio of CDs and APTES, realizing selectivity and sensitivity-oriented Cu(2+) sensing. The as-prepared probes (i.e., 3.33% APTES-0.9 mg mL(-1) CDs probe) show a synergistic amplification effect of CDs and APTES on enhancing the fluorescence signal of Cu(2+) detection through fluorescent self-quenching. The underlying mechanism can be ascribed to the stronger interaction including chelation and electrostatic attraction between Cu(2+) and N and O atoms-containing as well as negatively charged silica-coated CDs than other interference. Interestingly, colorimetric assay and Tyndall effect can be observed and applied to directly distinguish the concentration of Cu(2+) by the naked eye. The proposed fluorescent platform here has been successfully applied to monitor the alteration of striatum Cu(2+) in rat brain during the cerebral calm/sepsis process. The versatile properties of the probe provide a new and effective fluorescent platform for the sensing method in vivo sampled from the rat brain.
authors.affiliation: Department of Chemistry and ‡College of Resources Environment and Tourism, Capital Normal University , Beijing 100048, China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Chemistry and ‡College of Resources Environment and Tourism, Capital Normal University , Beijing 100048, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Chemistry and ‡College of Resources Environment and Tourism, Capital Normal University , Beijing 100048, China.
authors.forename: Linbo
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Chemistry and ‡College of Resources Environment and Tourism, Capital Normal University , Beijing 100048, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Chemistry and ‡College of Resources Environment and Tourism, Capital Normal University , Beijing 100048, China.
authors.forename: Kangyu
authors.initials: K
authors.lastname: Liu
authors.affiliation: Department of Chemistry and ‡College of Resources Environment and Tourism, Capital Normal University , Beijing 100048, China.
authors.forename: Keqing
authors.initials: K
authors.lastname: Wang
authors.affiliation: Department of Chemistry and ‡College of Resources Environment and Tourism, Capital Normal University , Beijing 100048, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002244:Carbon / Q000737:chemistry*; D003300:Copper / Q000032:analysis*; D045663:Quantum Dots; D051381:Rats; D012822:Silicon Dioxide / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D002244:Carbon; D012822:Silicon Dioxide; D003300:Copper
keywords: APTES; Cu2+ detection; carbon quantum dots; fluorescence; self-quenching