In this study, we developed an electrochemical sensor for sensitive detection of Cu²⁺ based on gold nanoflowers (AuNFs)‐modified electrode and DNAzyme functionalized Au@MIL‐101(Fe) (MIL: Materials of Institute Lavoisier). The AuNFs‐modified indium tin oxide modified conductive glass electrode(AuNFs/ITO) prepared via electrodeposition showed improved electronic transport properties and provided more active sites to adsorb large amounts of oligonucleotide substrate (DNA1) via thiol‐gold bonds. The stable Au@MIL‐101(Fe) could guarantee the sensitivity because of its intrinsic peroxidase mimic property, while the Cu²⁺‐dependent DNA‐cleaving DNAzyme linked to Au@MIL‐101(Fe) achieved the selectivity toward Cu²⁺. After the DNAzyme substrate strand (DNA2) was cleaved into two parts due to the presence of Cu²⁺, the oligonucleotide fragment linked to MIL‐101(Fe) was able to hybridize with DNA1 adsorbed onto the surface of AuNFs/ITO. Due to the peroxidase‐like catalytic activity of MIL‐101(Fe) and the affinity recognition property of DNAzyme toward Cu²⁺, the electrochemical biosensor showed a sensitive detection range from 0.001 to 100 μM, a detection limit of 0.457 nM and a high selectivity, demonstrating its potential for Cu²⁺ detection in real environmental samples.

中文翻译：

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基于纳米金修饰电极和DNA酶功能化Au @ MIL-101（Fe）的用于检测Cu2 +的电化学传感器

在这项研究中，我们开发了一种电化学传感器，用于基于金纳米花（AuNFs）修饰的电极和DNAzyme功能化的Au @ MIL-101（Fe）（MIL：Lavoisier研究所材料）敏感地检测Cu ²⁺。通过电沉积制备的AuNFs改性的铟锡氧化物改性的导电玻璃电极（AuNFs / ITO）具有改善的电子传输性能，并提供了更多的活性位点，可通过硫醇金键吸附大量寡核苷酸底物（DNA1）。稳定的Au @ MIL-101（Fe）可以保证灵敏度，因为其固有的过氧化物酶模拟特性，而与Au @ MIL-101（Fe）连接的Cu ²⁺依赖性DNA裂解DNA酶实现了对Cu ²⁺的选择性。。由于铜²⁺的存在，将DNAzyme底物链（DNA2）切割成两部分后，与MIL-101（Fe）连接的寡核苷酸片段能够与吸附在AuNFs / ITO表面的DNA1杂交。由于MIL-101（Fe）的过氧化物酶样催化活性和DNAzyme对Cu ²⁺的亲和识别特性，该电化学生物传感器的检测范围为0.001至100μM，检测限为0.457 nM，且检测限高。选择性，证明了其在实际环境样品中检测Cu ^2+的潜力。