Tunable Fluorescent Silica-Coated Carbon Dots: A Synergistic Effect for Enhancing the Fluorescence Sensing of Extracellular Cu2+ in Rat Brain

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• 作者：Yuqing Lin ; Chao Wang ; Linbo Li ; Hao Wang ; Kangyu Liu ; Keqing Wang ; Bo Li
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：December 16, 2015
• 年：2015
• 卷：7
• 期：49
• 页码：27262-27270
• 全文大小：591K
• ISSN：1944-8252

文摘

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 Cu²⁺ sensing. The as-prepared probes (i.e., 3.33% APTES-0.9 mg mL^鈥? CDs probe) show a synergistic amplification effect of CDs and APTES on enhancing the fluorescence signal of Cu²⁺ detection through fluorescent self-quenching. The underlying mechanism can be ascribed to the stronger interaction including chelation and electrostatic attraction between Cu²⁺ 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 Cu²⁺ by the naked eye. The proposed fluorescent platform here has been successfully applied to monitor the alteration of striatum Cu²⁺ 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.