School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences (UCAS), Beijing 100049, China.
Nanoscale. 2013 Oct 7;5(19):9340-7. doi: 10.1039/c3nr02522e. Epub 2013 Aug 19.
Fluorescent nanoparticles (NPs) for Al(3+) sensing with high selectivity were developed from a type of carbazole-based conjugated polymer with a two-dimensional donor-π bridge-acceptor (D-π-A) structure. These NPs are characterized by their small particle diameter (∼18 nm), far-red fluorescence emission (centered ∼710 nm), and Al(3+)-induced fluorescence enhancement with high selectivity owing to an Al(3+)-triggered inhibition on the intramolecular charge transfer (ICT) processes between the conjugated backbone and the pendant acceptors. This type of nanoparticle is easily suspended in aqueous solutions, indicating their practical applicability in physiological media, and their ability for intracellular Al(3+) sensing was confirmed. As compared to other types of conjugated polymer based probes showing metal ion mediated fluorescence quenching, these as-prepared NPs possess analyte-enhanced fluorescence emission, which is analytically favored in terms of sensitivity and selectivity. Fluorescence emission with wavelengths in the biological window of maximum optical transparency (∼700 to 1000 nm) is expected to impart a salient advantage for biological detection applications to these as-prepared probes. The superior features of merit of this new type of fluorescent probe, together with the validation of practicability for intracellular Al(3+) ion sensing, are indicative of their potential for application in fluorescence-based imaging and sensing, such as investigations on Al(3+)-related physiological and pathological processes.
基于咔唑的二维给体-π 桥-受体（D-π-A）结构的共轭聚合物制备了对 Al(3+)具有高选择性的荧光纳米粒子（NPs）用于 Al(3+)传感。这些 NPs 的特点是粒径小（∼18nm）、远红光荧光发射（中心在∼710nm），并且由于 Al(3+)触发的共轭骨架和侧挂受体之间的分子内电荷转移（ICT）过程的抑制，具有高选择性的 Al(3+)诱导荧光增强。这种类型的纳米粒子很容易悬浮在水溶液中，表明它们在生理介质中的实际适用性，并且证实了它们用于细胞内 Al(3+)传感的能力。与其他显示金属离子介导荧光猝灭的共轭聚合物基探针相比，这些制备的 NPs 具有分析物增强的荧光发射，从灵敏度和选择性的角度来看，这在分析上是有利的。在生物光学透明性最大的生物窗口（∼700 至 1000nm）内的荧光发射有望为这些制备的探针在生物检测应用中带来显著优势。这种新型荧光探针的卓越特性，以及对细胞内 Al(3+)离子传感实用性的验证，表明它们有可能应用于荧光成像和传感，例如对 Al(3+)相关的生理和病理过程的研究。
