Ho Feng-Cheng, Huang Kuan-Hsiang, Cheng Hung-Wei, Huang Yi-Jing, Nhien Pham Quoc, Wu Chia-Hua, Wu Judy I, Chen San-Yuan, Lin Hong-Cheu
Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan.
Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan.
Dyes Pigm. 2021 May;189. doi: 10.1016/j.dyepig.2021.109238. Epub 2021 Feb 21.
A novel aggregation-induced emission (AIE) structure containing a tetraphenylethene (TPE) unit covalently linked with a merocyanine (MC) unit was synthesized and investigated in semi-aqueous solutions with 90% water fraction. The open-form structure of red-emissive MC unit combined with TPE unit was utilized as a bi-fluorophoric sensor to detect lead(II) ion, which could be transformed from the close-form structure of non-emissive SP unit upon UV exposure. Moreover, the TPE unit as an energy donor with the blue-green photoluminescence (PL) emission at 480 nm was combined with the MC unit as an energy acceptor with the red PL emission at 635 nm. Due to the Förster resonance energy transfer (FRET) processes, the bi-fluorophoric sensor produced more efficient ratiometric PL behavior to induce a stronger red PL emission than that of the mono-fluorophoric MC unit. Hence, the PL sensor responses of the AIE bi-fluorophoric structure toward lead(II) ion could be further amplified via the FRET-OFF processes to turn off red PL emission of the coordinated MC acceptor and to recover blue-green PL emission of the TPE donor. Accordingly, the best LOD value for the AIE sensor detection toward Pb was 0.27 μM. The highest red MC emission with the optimum FRET process of AIE sensor could be utilized in cell viability tests to prove the non-toxic and remarkable bio-marker of AIE sensor to detect lead(II) ion in live cells. The developed FRET-OFF processes with ratiometric PL behavior of the bi-fluorophoric AIE sensor can be utilized for future chemo- and bio-sensor applications.
合成了一种新型的聚集诱导发光（AIE）结构，该结构包含一个与部花青（MC）单元共价连接的四苯乙烯（TPE）单元，并在水含量为90%的半水溶液中进行了研究。红色发光的MC单元与TPE单元的开放形式结构被用作双荧光传感器来检测铅（II）离子，在紫外线照射下，它可以从非发光的SP单元的封闭形式结构转变而来。此外，作为能量供体的TPE单元在480 nm处有蓝绿色光致发光（PL）发射，与作为能量受体的MC单元在635 nm处有红色PL发射相结合。由于Förster共振能量转移（FRET）过程，双荧光传感器产生了更有效的比率PL行为，从而诱导出比单荧光MC单元更强的红色PL发射。因此，AIE双荧光结构对铅（II）离子的PL传感器响应可以通过FRET-OFF过程进一步放大，以关闭配位的MC受体的红色PL发射，并恢复TPE供体的蓝绿色PL发射。相应地，AIE传感器检测铅的最佳检测限（LOD）值为0.27 μM。具有最佳FRET过程的AIE传感器的最高红色MC发射可用于细胞活力测试，以证明AIE传感器在活细胞中检测铅（II）离子的无毒且显著的生物标志物特性。所开发的具有双荧光AIE传感器比率PL行为的FRET-OFF过程可用于未来的化学和生物传感器应用。
