Department of Chemistry, Fudan University, Songhu Road 2005, Shanghai, 200438, China.
Laboratory of Biophysics, University of Turku, FI-20014, Turku, Finland.
Mikrochim Acta. 2019 Jul 30;186(8):584. doi: 10.1007/s00604-019-3674-4.
The construction of multiple fluorescent nanosensors for intracellular studies is a challenging task because spectral overlap of indicator probes can lead to cross-talk and mutual interference. This work describes biodegradable nanosensors that can simultaneously measure three intracellular parameters (temperature, pH and oxygen concentration). Bovine serum albumin (BSA) is selected as the scaffold to construct the triple nanosensor by covalent immobilization four fluorophores on BSA. The following luminophores were used: (a) fluorescein as a probe for pH values, (b) a platinum(II) porphyrin complex for oxygen; (c) a europium(III) clathrate complex for temperature, and (d) a rhodamine B as a reference dye. The nanoparticles have a size of 20 nm and show excellent biocompatibility and good brightness. The nanosensors were used for ratiometric imaging of intracellular pH values, oxygen and temperature in HeLa cells. The triple nanosensor responds reversibly and this can be used for real-time tracing of these key parameters. Owing to their biodegradable feature, the use of this kind of triple nanosensor reduce the stress on cellular activities because less nanosensors can be used to gather the total information. Graphical abstractA triple nanosensor for simultaneously ratiometrically sensing intracellular pH, oxygen and temperature values was constructed by covalently labelling four fluorophores on a single serum albumin protein. The nanosensor shows good sensitivity, biocompatibility, is biodegradable and suitable for continuously measuring these important parameters.
用于细胞内研究的多种荧光纳米传感器的构建是一项具有挑战性的任务，因为指示剂探针的光谱重叠会导致串扰和相互干扰。本工作描述了可同时测量三个细胞内参数（温度、pH 值和氧浓度）的可生物降解纳米传感器。牛血清白蛋白（BSA）被选为支架，通过将四个荧光团共价固定在 BSA 上来构建三重纳米传感器。使用了以下发光团：（a）荧光素作为 pH 值探针，（b）铂（II）卟啉配合物作为氧探针；（c）铕（III）笼状配合物作为温度探针，（d）罗丹明 B 作为参考染料。纳米粒子的尺寸为 20nm，具有优异的生物相容性和良好的亮度。该纳米传感器用于 HeLa 细胞内 pH 值、氧和温度的比率成像。三重纳米传感器可进行可逆响应，可用于这些关键参数的实时追踪。由于其可生物降解的特性，这种三重纳米传感器的使用减少了对细胞活动的压力，因为可以使用更少的纳米传感器来收集总信息。图摘要通过将四个荧光团共价标记在单个血清白蛋白蛋白上，构建了用于同时比率检测细胞内 pH 值、氧和温度值的三重纳米传感器。该纳米传感器具有良好的灵敏度、生物相容性、可生物降解性，适合连续测量这些重要参数。
