Anal Chem. 2018 Mar 6;90(5):3563-3569. doi: 10.1021/acs.analchem.8b00006. Epub 2018 Feb 16.
Copper indium sulfide (CuInS, CIS) nanocrystals (NCs) are a promising solution to the toxic issue of Cd- and Pb-based NCs. Herein, electrochemiluminescence (ECL) of CIS NCs in aqueous medium is investigated for the first time with l-glutathione and sodium citrate-stabilized water-soluble CIS/ZnS NCs as model. The CIS/ZnS NCs can be oxidized to hole-injected states via electrochemically injecting holes into valence band at 0.55 and 0.94 V (vs Ag/AgCl), respectively. The hole-injected state around 0.94 V can bring out efficient oxidative-reduction ECL with a similar color to Ru(bpy) in the presence of tri- n-propylamine (TPrA) and enable CIS/ZnS NCs promising ECL tags with l-glutathione as linker for labeling. The ECL of CIS/ZnS NCs/TPrA can be utilized to determine vascular endothelial growth factor (VEGF) from 0.10 to 1000 pM with the limit of detection at 0.050 pM (S/N = 3). Although the hole-injected state around 0.55 V is generated ahead of oxidation of TPrA and fails to bring out coreactant ECL, annihilation ECL proves that both hole-injected states generated, at 0.55 and 0.94 V, can be involved in electrochemical redox-induced radiative charge transfer by directly stepping CIS/ZnS NCs from electron-injecting potential to hole-injecting potential. CIS/ZnS NCs are promising nontoxic electrochemiluminophores with lowered ECL triggering potential around 0.55 V for less electrochemical interference upon the development of coreactant.
铜铟硫（CuInS，CIS）纳米晶体（NCs）是解决 Cd 和 Pb 基 NCs 毒性问题的一种很有前途的方法。在此，首次研究了在水溶液中，L-谷胱甘肽和柠檬酸钠稳定的水溶性 CIS/ZnS NCs 作为模型，CIS NCs 的电致化学发光（ECL）。CIS/ZnS NCs 可以通过在 0.55 和 0.94 V（相对于 Ag/AgCl）处电化学注入空穴到价带，被氧化到空穴注入状态。0.94 V 左右的空穴注入态可以在存在三正丙胺（TPrA）的情况下，引发与 Ru（bpy）相似颜色的高效氧化还原 ECL，并且 CIS/ZnS NCs 可以作为标记物，与 L-谷胱甘肽作为连接物一起，有望成为 ECL 标签。CIS/ZnS NCs/TPrA 的 ECL 可以用于从 0.10 到 1000 pM 的血管内皮生长因子（VEGF）的测定，检测限为 0.050 pM（S/N = 3）。虽然 0.55 V 左右的空穴注入态在 TPrA 氧化之前产生，并且不能引发共反应物 ECL，但湮灭 ECL 证明，在电子注入势到空穴注入势之间直接跨越时，在 0.55 和 0.94 V 产生的两种空穴注入态都可以参与电化学氧化还原诱导的辐射电荷转移。CIS/ZnS NCs 是很有前途的无毒电致发光体，其 ECL 触发电位约为 0.55 V，在共反应物的发展过程中，电化学干扰较小。
