Fabrication of Noncoplanar Molecule Aggregates with Inherent Porous Structures for Electrochemiluminescence Signal Amplification

Abstract

A simple and time-saving strategy was developed for the amplification of electrochemiluminescence (ECL) by dropping the noncoplanar tetraphenylethylene (TPE) solution on the surface of gold electrode. The self-assembled TPE aggregates exhibited inherent porous structures, endowing them with high specific surface area and oxygen adsorption capability. Therefore, the fabricated porous structures could lead to a 50-fold increase in the ECL signal of luminol in neutral aqueous solution, in comparison to that on the bare electrode. In contrast, the aggregates of the two typical coplanar polycyclic aromatic hydrocarbons (PAHs), perylene and pyrene, gave a weaker ECL enhancement, owing to their disc-like molecular structure and densely packed layers under aggregated conditions. The proposed ECL system has been successfully applied for the detection of hydrogen peroxide (HO) in the linear range of 0.25-1000 μM with a detection limit (S/N = 3) of 0.1 μM. Our findings provide inspiration for revealing the role of inherent molecular structure in the aggregate configuration, and they provide attractive perspectives for the usage of noncoplanar molecules in analytical applications.

Electrochemiluminescence Enhanced by Restriction of Intramolecular Motions (RIM): Tetraphenylethylene Microcrystals as a Novel Emitter for Mucin 1 Detection

“…Basic physics tells us that any intramolecular motions will consume energy, thereby weakening or even eliminating the radiative emissions of the molecule. However, in aqueous solution, the TPE was completely insoluble and had a tendency to aggregate in an incompact and amorphous manner, 24 thanks to the steric effect between the moving phenyl rotors. Therefore, we speculated that the restriction of intramolecular motions (RIM) was a major cause for the ECL enhancement.…”

Substituent-Induced Aggregated State Electrochemiluminescence of Tetraphenylethene Derivatives

“…As for organic-based TPE derivatives, although the mechanism between fluorescence and ECL is similar to a large extent, only a few studies have involved their ECLs, and there are way less than for their fluorescence studies. Very recently, Lu and co-workers reported that the TPE aggregates on the surface of the gold electrode could significantly enhance the ECL signal of luminol in neutral aqueous solution due to its porous noncoplanar structure . Ju and co-workers synthesized the donor–acceptor conjugated polymer dots for tunable ECL activated by AIE-active TPE moieties .…”

Metal-organic Frameworks (MOF)-based Novel Electrochemiluminescence Biosensing Platform for Quantification of H2O2 Releasing from Tumor Cells

“…尽管 Bard 等 [13] 采用乳化 法制备了红荧烯和 DPA 的水包油乳状液滴, 实现了在 水相中的 ECL, 然而乳液体系的稳定性还需进一步提 高 . 在 我 们 的 前 期 研 究 中 , 采 用 再 沉 淀 法 合 成 了 DPA [14] 、 红荧烯 [15] 和四苯基乙烯 [16] 的微纳晶体极大地改 善了多环芳烃发光体在水相中的稳定性, 获得了显著增 强的 ECL 响应. 进一步的研究发现, 再沉淀法合成的微 纳晶体其尺寸、形貌容易受到合成条件(如表面活性剂 的种类、用量、反应过程中的温度和反应时间等)的影 响, 导致不同形貌的微纳晶体的 ECL 光谱相对于其单 体的光谱呈现红移和展宽 [17][18] .…”