Department of Chemistry & The State Key Laboratory of Molecular Engineering of Polymers & Institute of Biomedicine Science, Fudan University , Shanghai 200433, P. R. China.
ACS Appl Mater Interfaces. 2014 Jul 23;6(14):11190-7. doi: 10.1021/am501249p. Epub 2014 Apr 24.
The fabrication of lanthanide upconversion nanocomposites as probes has become a new research hotspot due to its special advantages via utilizing upconversion luminescence (UCL) as a detection signal. Herein, a hybrid organic dye modified upconversion nanophosphor is successfully developed as a nanoprobe for cysteine/homocysteine. Yolk-shell structured upconversion nanoparticles (YSUCNP) with lanthanide upconversion nanophosphor as moveable core and silica as mesoporous shell are synthesized, and a colorimetric chemodosimeter for cysteine/homocysteine is accommodated in the hollow cavities. Thus, cysteine/homocysteine can be quantitatively detected on the basis of luminescent resonance energy transfer (LRET) in a UCL turn-off pattern. The dye-loaded YSUCNP possess good dispersibility in aqueous solution; thus detection of the targeted molecule can be achieved in pure water. Cellular experiments carried out with laser-scanning upconversion luminescence microscopy further demonstrate that the dye-loaded YSUCNP can serve as an intracellular nanoprobe to detect cysteine/homocysteine. Moreover, this dye-loading protocol can be developed as a common approach to construct other chemodosimeter-modified UCNP hybrid nanoprobes, as proved by a UCL turn-on style sensor for cyanide.
由于上转换发光（UCL）作为检测信号具有特殊优势，因此将镧系元素上转换纳米复合材料制成探针已成为新的研究热点。本文成功开发了一种杂化有机染料修饰的上转换纳米荧光粉作为半胱氨酸/同型半胱氨酸的纳米探针。合成了具有上转换纳米荧光粉作为可动核和二氧化硅作为介孔壳的核壳结构上转换纳米粒子（YSUCNP），并在中空腔体内容纳了用于半胱氨酸/同型半胱氨酸的比色化学计量法。因此，可以根据 UCL 关闭模式中的荧光共振能量转移（LRET）定量检测半胱氨酸/同型半胱氨酸。负载染料的 YSUCNP 在水溶液中具有良好的分散性，因此可以在纯水中进行目标分子的检测。用激光扫描上转换荧光显微镜进行的细胞实验进一步证明，负载染料的 YSUCNP 可用作检测半胱氨酸/同型半胱氨酸的细胞内纳米探针。此外，通过用于氰化物的 UCL 开启式传感器证明，这种染料负载方案可以作为构建其他化学计量法修饰的 UCNP 杂化纳米探针的通用方法。
