College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, China.
Anal Chem. 2021 Apr 6;93(13):5635-5643. doi: 10.1021/acs.analchem.1c00470. Epub 2021 Mar 22.
When fabricating ratiometric optical probes using lanthanide-doped upconversion nanoparticles (UCNPs), which are promising luminescent materials that have widely been utilized in biosensing and bioimaging as energy donors, it is still a challenge to obtain the emission signal of energy acceptors with reasons unclear so far. Herein, we reveal that the energy-transfer efficiency and brightness of UCNPs as well as the aggregation-caused quenching (ACQ) of energy accepting dyes are the main factors restricting the emission of energy acceptors, and we have circumvented this problem by modulating the structure of UCNPs and the assembly manner of the energy donor-acceptor pair. On this basis, a proof-of-concept ratiometric upconversion nanoprobe was constructed for hydrogen sulfide (HS) detection with an elaborate dye Fl-1 as an energy acceptor. As the HS concentration increased, the emission intensity of Fl-1 at 525 nm increased gradually, accompanied by a decrease of upconversion luminescence at 480 nm, thus providing a ratiometric signal of / dependent on the HS concentration. This probe was able to track HS in living cells and zebrafish and visualize the HS level of mice in physiological processes.
在使用镧系掺杂上转换纳米粒子（UCNPs）制造比率光学探针时，尽管这些发光材料作为能量供体在生物传感和生物成像中得到了广泛应用，但仍然存在一个挑战，即到目前为止，其原因尚不清楚如何获得能量受体的发射信号。在此，我们揭示了能量转移效率和 UCNPs 的亮度以及能量接受染料的聚集猝灭（ACQ）是限制能量受体发射的主要因素，我们通过调节 UCNPs 的结构和能量供体-受体对的组装方式来解决这个问题。在此基础上，我们构建了一个基于比率上转换的纳米探针，用于检测硫化氢（HS），其中精心设计的染料 Fl-1 作为能量受体。随着 HS 浓度的增加，Fl-1 在 525nm 处的发射强度逐渐增加，同时伴随着 480nm 处上转换发光的降低，从而提供了一个与 HS 浓度相关的比率信号。该探针能够在活细胞和斑马鱼中追踪 HS，并在生理过程中可视化小鼠的 HS 水平。
