Fluorescence resonance energy transfer-based ratiometric fluorescent probe for detection of Zn(2+) using a dual-emission silica-coated quantum dots mixture.
Fluorescence resonance energy transfer-based ratiometric fluorescent probe for detection of Zn(2+) using a dual-emission silica-coated quantum dots mixture.
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DOI：
10.1021/acs.analchem.5b00514
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发表时间：
2015-05
影响因子：
7.4
通讯作者：
Liang Wu;Qing Guo;Yuqian Liu;Qing Sun
中科院分区：
文献类型：
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作者：
Liang Wu;Qing Guo;Yuqian Liu;Qing Sun
本文报道了一种以不同颜色的量子点为双荧光载体，以超薄硅胶外壳为间隔基团，以Meso-四(4-磺酸苯基)卟啉二盐酸盐(TSPP)为受体的新型比率荧光探针的设计和应用，用于水溶液和活细胞中锌离子的检测。在我们设计的探针结构中，硅壳在控制量子点、TSPP和锌(2+)的位置，防止量子点与锌(2+)的直接接触方面发挥了关键作用，但提供了从双色量子点到TSPP的荧光共振能量转移(FRET)。在Zn(2+)存在下，分析物-受体反应改变了TSPP在Q带的吸收，相应地改变了从双色量子点到受体的两个独立的FRET过程的效率，导致绿色发射量子点的荧光增强，而黄色发射量子点的荧光猝灭。得益于不同颜色量子点良好的双发射分辨率和较大的发射比范围，探针溶液显示出从黄色到绿色的连续颜色变化，这是肉眼可以清楚观察到的。在生理条件下，该探针对0.3~6μM的锌离子有稳定的响应，在水溶液中的检出限为6 0 nM。与单发射探针相比，该比率探针对锌(2+)的选择性优于其他重要的生理阳离子，如Fe(3+)和Cu2+。它已初步用于活体细胞中锌离子的比率成像，获得了满意的分辨率。
In this work, we report the design and application of a new ratiometric fluorescent probe, which contains different-colored quantum dots (QDs) as dual fluorophores, ultrathin silica shell as spacer, and meso-tetra(4-sulfonatophenyl)porphine dihydrochloride (TSPP) as receptor, for Zn(2+) detection in aqueous solution and living cells. In the architecture of our designed probe, the silica shell plays the key roles in controlling the locations of QDs, TSPP, and Zn(2+), preventing the direct contact between QDs and Zn(2+) but affording fluorescence resonance energy transfer (FRET) from dual-color QDs to TSPP. In the presence of Zn(2+), the analyte-receptor reaction changes the absorption in the range of the Q-band of TSPP and accordingly the efficiencies of two independent FRET processes from the dual-colored QDs to the acceptor, respectively, leading to fluorescence enhancement of green-emission QDs whereas fluorescence quenching of yellow-emission QDs. Benefiting from the well-resolved dual emissions from different-colored QDs and the large range of emission ratios, the probe solution displays continuous color changes from yellow to green, which can be clearly observed by the naked eye. Under physiological conditions, the probe exhibits a stable response for Zn(2+) from 0.3 to 6 μM, with a detection limit of 60 nM in aqueous solutions. With respect to single-emission probes, this ratiometric probe has demonstrated to feature excellent selectivity for Zn(2+) over other physiologically important cations such as Fe(3+) and Cu(2+). It has been preliminarily used for ratiometric imaging of Zn(2+) in living cells with satisfying resolution.