Molecular Sciences and Biomedicine Laboratory (MBL), State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, and College of Biology, Collaborative Innovation Center for Molecular Engineering and Theranostics, Hunan University , Changsha, Hunan 410082, China.
Anal Chem. 2016 Feb 2;88(3):1639-46. doi: 10.1021/acs.analchem.5b03573. Epub 2016 Jan 20.
Upconversion nanoparticles (UCNPs) possess several unique features, but they suffer from surface quenching effects caused by the interaction between the UCNPs and fluorophore. Thus, the use of UCNPs for target-induced emission changes for biosensing and bioimaging has been challenging. In this work, fluorophore and UCNPs are effectively separated by a silica transition layer with a thickness of about 4 nm to diminish the surface quenching effect of the UCNPs, allowing a universal and efficient luminescence resonance energy transfer (LRET) ratiometric upconversion luminescence nanoplatform for biosensing applications. A pH-sensitive fluorescein derivative and Hg(2+)-sensitive rhodamine B were chosen as fluoroionphores to construct the LRET nanoprobes. Both showed satisfactory target-triggered ratiometric upconversion luminescence responses in both solution and live cells, indicating that this strategy may find wide applications in the design of nanoprobes for various biorelated targets.
上转换纳米粒子（UCNPs）具有多种独特的特性，但它们受到 UCNPs 与荧光团之间相互作用引起的表面猝灭效应的影响。因此，将 UCNPs 用于基于目标诱导的发射变化的生物传感和生物成像一直具有挑战性。在这项工作中，通过厚度约为 4nm 的二氧化硅过渡层将荧光团和 UCNPs 有效分离，以减弱 UCNPs 的表面猝灭效应，从而为生物传感应用提供一种通用且高效的荧光共振能量转移（LRET）比率上转换发光纳米平台。选择对 pH 敏感的荧光素衍生物和对 Hg(2+)敏感的罗丹明 B 作为荧光团来构建 LRET 纳米探针。两者在溶液和活细胞中均表现出令人满意的靶触发比率上转换发光响应，表明该策略可能在设计用于各种生物相关靶标的纳米探针方面具有广泛的应用。
