Cao Zhiyuan, Shu Yufei, Qin Haiyan, Su Bin, Peng Xiaogang
Center for Chemistry of High-Performance & Novel Materials, Institute of Analytical Chemistry, Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
ACS Cent Sci. 2020 Jul 22;6(7):1129-1137. doi: 10.1021/acscentsci.0c00484. Epub 2020 Jun 1.
Outstanding photoluminescence (PL) and electroluminescence properties of quantum dots (QDs) promise possibilities for them to meet challenging expectations of electrochemiluminescence (ECL), which at present relies on inefficient and spectral-irresolvable emitters based on transition-metal complexes (such as Ru(bpy) ). However, ECL is reported to be extremely sensitive to the surface traps on the QDs likely because of the spatially and temporally separated electrochemical charge injections. Results here reveal that, by engineering the interior inorganic structure (CdSe/CdS/ZnS core/shell/shell structure) and inorganic-organic interface using new synthetic methods, the trap-insensitive QDs with near-unity PL quantum yield and monoexponential PL decay dynamics in water generated narrow band-edge ECL with efficiencies about six orders of magnitude higher than that of the standard Ru(bpy) . The band-edge and spectrally resolved ECL from CdSe/CdS/ZnS core/shell/shell QDs demonstrated a new readout scheme using electrochemical potential. Excellent ECL performance of QDs uncovered here offer opportunities to realize the full potential of ECL for biomedical detection and diagnosis.
量子点（QDs）出色的光致发光（PL）和电致发光特性使其有望满足电化学发光（ECL）的挑战性期望，目前ECL依赖于基于过渡金属配合物（如Ru(bpy) ）的低效且光谱不可分辨的发光体。然而，据报道ECL对量子点表面陷阱极其敏感，这可能是由于电化学电荷注入在空间和时间上是分离的。此处结果表明，通过使用新的合成方法设计内部无机结构（CdSe/CdS/ZnS核/壳/壳结构）和无机-有机界面，在水中具有近单位PL量子产率和单指数PL衰减动力学的对陷阱不敏感的量子点产生了窄带边ECL，其效率比标准Ru(bpy) 高约六个数量级。来自CdSe/CdS/ZnS核/壳/壳量子点的带边和光谱分辨ECL展示了一种使用电化学势的新读出方案。此处发现的量子点出色的ECL性能为实现ECL在生物医学检测和诊断方面的全部潜力提供了机会。
