Herein, a credible construction strategy to improve electrochemiluminescence (ECL) of luminol was developed based on Cu2O-Au heterostructures. Summarily, gold nanoparticles (AuNPs) were anchored on surface of Cu2O nanocube (Cu2O@AuNPs) by spontaneous reduction reaction. Then, luminol molecules were concentrated on Cu2O@AuNPs using L-Cysteine (Cys) as covalent linkage to build the composite emitter (Cu2O@AuNPs-Cys-luminol). The enhancement mechanism was realized by following aspects: (I) Cu2O@AuNPs worked as electrocatalyst for glucose to generate coreactant of H2O2 in situ, avoiding the instability of direct addition of H2O2. (II) luminol molecules were firmly attached on Cu2O@AuNPs to achieve centralized and strong luminescence at low consumption. (III) Cys acted as an intramolecular coreactant and directly linked to luminol to increase luminous efficiency. To validate the effectiveness, a sandwiched immunoassay was built using concanavalinA (ConA) as analyte. Electroreduced graphene film as substrate provided phenoxy-derivatized dextran (DexP) with abundant binding sites and improved conductivity. To improve the specificity, DexP was used to identify ConA via the specific carbohydrate-ConA interaction. Then, Cu2O@AuNPs-Cys-luminol was modified on electrode as ECL signal indicator. The ECL immunosensor achieved determination of ConA with low detection limit of 2.9 × 10-5 ng/mL and excellent stability of continuous potential scan for 8 cycles. Experimental results demonstrated that the proposed construction strategy made considerable progress in ECL efficiency and stability of luminol. The creational pattern of construction strategy achieves high detection capabilities to ConA and expands the applicability of luminol in ECL system. It is expected to have more potential application value in immunoassay with universality.

中文翻译：

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基于Cu2O-Au异质结构增强了鲁米诺的电化学发光，实现了多重扩增策略。

本文中，基于Cu2O-Au异质结构，开发了一种可靠的构建策略来改善鲁米诺的电化学发光（ECL）。总之，通过自发还原反应将金纳米颗粒（AuNPs）固定在Cu2O纳米立方体（Cu2O @ AuNPs）的表面上。然后，以L-半胱氨酸（Cys）作为共价键将鲁米诺分子浓缩在Cu2O @ AuNPs上，以构建复合发光体（Cu2O @ AuNPs-Cys-luminol）。增强机理可通过以下几个方面实现：（I）Cu2O @ AuNPs作为葡萄糖的电催化剂，原位生成H2O2的共反应剂，避免了直接添加H2O2的不稳定性。（II）鲁米诺分子牢固地附着在Cu2O @ AuNPs上，从而以较低的消耗实现集中且强的发光。（III）Cys充当分子内共反应剂并直接连接至鲁米诺以增加发光效率。为了验证有效性，使用刀豆球蛋白A（ConA）作为分析物建立了夹心免疫测定法。电还原石墨烯薄膜为底物提供了具有丰富的结合位点和改善的导电性的苯氧基衍生的葡聚糖（DexP）。为了提高特异性，DexP用于通过特定的碳水化合物与ConA相互作用鉴定ConA。然后，在电极上修饰Cu2O @ AuNPs-Cys-鲁米诺作为ECL信号指示剂。ECL免疫传感器可以以2.9×10-5 ng / mL的低检测限实现ConA的测定，并且连续电势扫描8个循环均具有出色的稳定性。实验结果表明，提出的施工策略在鲁米诺的ECL效率和稳定性方面取得了长足的进步。该构建策略的创新模式实现了对ConA的高检测能力，并扩展了鲁米诺在ECL系统中的适用性。有望在普遍性的免疫分析中具有更多潜在的应用价值。