Ratiometric fluorescent nanosensors for selective detecting cysteine with upconversion luminescence
Ratiometric fluorescent nanosensors for selective detecting cysteine with upconversion luminescence
复制标题
用于通过上转换发光选择性检测半胱氨酸的比率荧光纳米传感器
DOI：
10.1016/j.bios.2015.09.034
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发表时间：
2016-03-15
影响因子：
12.6
通讯作者：
Zhang, Ligong
中科院分区：
文献类型：
--
作者：
Guan, Yunlong;Qu, Songnan;Zhang, Ligong
基于上转换（UC）发光的荧光传感器由于其深穿透性、最小的自身荧光和比例荧光输出等优点，被认为是一种很有前途的检测生物分析物的策略。因此，设计了一种纳米传感器的原型，该传感器结合了介孔二氧化硅涂层的上转换纳米颗粒（UCNPs）和负载在孔中的基于荧光素的荧光探针来检测半胱氨酸（Cys）。二氧化硅外壳为探针提供了装载空间，并使纳米传感器能够分散在水中。在Cys存在下，将荧光探针转化为5(6)-羧基荧光素，发射波段以518 nm为中心，由980 nm近红外激光驱动的NaYF4:Yb-3+， Tm-3+ UCNPs在475 nm左右的光二次激发。在20 ~ 200 μ mol L-1范围内，随着Cys浓度的增加，绿蓝发光强度比（I-518/I-475）呈指数增长。纳米传感器对Cys的响应可以通过肉眼的发光颜色变化来识别。有证据表明，这些纳米传感器能够在水溶液中感应Cys，并以动力学控制的选择性将Cys与同型半胱氨酸（Hcy）区分开来。进一步将该系统用于人血清中Cys的检测，结果与高效液相色谱法检测结果一致，回收率可接受。(C) 2015 Elsevier B.V.版权所有
Fluorescent sensors based on upconversion (UC) luminescence have been considered as a promising strategy to detect bio-analyte due to their advantages in deep penetration, minimum autofluorescence, and ratiometric fluorescent output. A prototype of nanosensors combined with mesoporous silica coated upconversion nanoparticles (UCNPs) and a fluorescein-based fluorescent probe loaded in pores was therefore designed to detect cysteine (Cys). The silica shell provided loading space for the probe and enabled the nanosensors to disperse in water. In the presence of Cys, the fluorescent probe was transformed into 5(6)-carboxyfluorescein with an emission band centering at 518 nm which was secondarily excited by the light at around 475 nm from NaYF4:Yb-3+, Tm-3+ UCNPs driven by 980 nm near-infrared (NIR) laser. The intensity ratio between green and blue luminescence (I-518/I-475) grew exponentially with increasing concentrations of Cys over a range of 20-200 mu mol L-1. The response of the nanosensors towards Cys was recognizable with naked eyes by luminescence color change. Evidences suggest that these nanosensors are capable of sensing Cys in aqueous solution and distinguishing Cys from homocysteine (Hcy) with kinetically-controlled selectivity. The system was further employed to detect Cys in human serum and the result was in agreement with it tested by high performance liquid chromatography with acceptable recovery. (C) 2015 Elsevier B.V. All rights reserved.