Chang Yi-Hsuan, Chiang Wei-Hung, Ilhami Fasih Bintang, Tsai Cheng-Yu, Huang Sin-Yu, Cheng Chih-Chia
Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan.
J Colloid Interface Sci. 2023 May;637:389-398. doi: 10.1016/j.jcis.2023.01.104. Epub 2023 Jan 25.
We present a new, insightful donor-acceptor (D-A) energy transfer-based strategy for the preparation and development of water-soluble multifunctional pH-responsive heterojunction nanoparticles. Hydrophilic tertiary amine-grafted polythiophene (WPT) as a donor and blue fluorescent graphene quantum dots (GQD) as an acceptor spontaneously form co-assembled nanoparticles that function as a highly pH-sensitive and efficient biosensor appropriate for the detection of cancer cells. These WPT/GQD nanoparticles exhibit a number of unique physical characteristics-such as broad-range, tunable GQD-loading contents and particle sizes, extremely low cytotoxicity in normal and cancer cells, and highly sensitive pH-responsiveness and rapid acid-triggered fluorescent behavior under aqueous acidic conditions. We show these features are conferred by self-aggregation of the GQD within the nanoparticles and subsequent aggregation-induced fluorescence of GQD after disassembly of the nanoparticles and dissociation of the D-A interactions under acidic conditions. Importantly, in vitro fluorescence imaging experiments clearly demonstrated the WPT/GQD nanoparticles were gradually taken up into normal and cancer cells in vitro. Selective formation of GQD aggregates subsequently occurred in the acidic microenvironment of the cancer cells and the interior of the cancer cells exhibited strong blue fluorescence; these phenomena did not occur in normal cells. In contrast, pristine WPT and GQD did not exhibit cellular microenvironment-triggered fluorescence transitions in cancer or normal cell lines. Therefore, this newly discovered water-soluble heterojunction system may represent a strongly fluorescent highly pH-sensitive bioprobe for rapid detection of cancer cells.
我们提出了一种基于供体-受体（D-A）能量转移的新颖且有洞察力的策略，用于制备和开发水溶性多功能pH响应性异质结纳米颗粒。亲水性叔胺接枝聚噻吩（WPT）作为供体，蓝色荧光石墨烯量子点（GQD）作为受体，自发形成共组装纳米颗粒，该纳米颗粒可作为一种高度pH敏感且高效的生物传感器，适用于癌细胞检测。这些WPT/GQD纳米颗粒具有许多独特的物理特性，如宽范围、可调节的GQD负载量和粒径、在正常细胞和癌细胞中极低的细胞毒性，以及在水性酸性条件下高度敏感的pH响应性和快速的酸触发荧光行为。我们表明，这些特性是由纳米颗粒内GQD的自聚集以及随后在酸性条件下纳米颗粒解体和D-A相互作用解离后GQD的聚集诱导荧光赋予的。重要的是，体外荧光成像实验清楚地表明，WPT/GQD纳米颗粒在体外逐渐被正常细胞和癌细胞摄取。随后，GQD聚集体在癌细胞的酸性微环境中选择性形成，癌细胞内部呈现出强烈的蓝色荧光；这些现象在正常细胞中未发生。相比之下，原始的WPT和GQD在癌细胞或正常细胞系中未表现出细胞微环境触发的荧光转变。因此，这种新发现的水溶性异质结系统可能代表一种用于快速检测癌细胞的强荧光、高度pH敏感的生物探针。
