School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
School of Energy and Environment & Department of Materials Science and Engineering, City University of Hong Kong, Kowloon Tong, 999077 Hong Kong, China.
Anal Chem. 2021 Feb 16;93(6):3295-3300. doi: 10.1021/acs.analchem.0c05342. Epub 2021 Feb 2.
Redox mediators can facilitate the electrochemical communication between targets and electrodes for material characterization and investigation. To provide an alternative to the chemical-based redox mediators, herein, we present a nanoparticle-based redox mediator, i.e., the trisodium citrates (TSC)-capped triangular silver nanoplates (Tri-Ag-NP), which demonstrates an efficient oxidative process at around 0.13 V (vs Ag/AgCl) with acceptable redox reversibility by exploiting the interaction between the carbonyl group of TSC and the Ag element of Tri-Ag-NP. The TSC of Tri-Ag-NPs can be selectively replaced by thiols and enable the obtained Tri-Ag-NP with changed electrochemical redox response, which could be utilized to determine various thiols at 0.13 V, a much lowered oxidative potential than traditional redox mediators, with a similar linear response range, response slope, and limit of detection (LOD). This work proposes a surface-engineering approach to design and develop electrochemical redox probes using Ag nanoparticles with particular morphology, indicating that the interaction between the carbonyl group and Ag nanoparticles might be extended to sensing application beyond the surface-enhanced Raman scattering.
氧化还原介体可以促进目标物和电极之间的电化学通讯，用于材料特性研究。为了提供一种替代基于化学的氧化还原介体的方法，本研究提出了一种基于纳米颗粒的氧化还原介体，即柠檬酸三钠（TSC）封端的三角银纳米片（Tri-Ag-NP），它通过利用 TSC 的羰基与 Tri-Ag-NP 的 Ag 元素之间的相互作用，在大约 0.13 V（相对于 Ag/AgCl）的氧化过程中表现出高效的氧化过程，并且具有可接受的氧化还原可逆性。Tri-Ag-NP 的 TSC 可以被巯基选择性取代，并使获得的 Tri-Ag-NP 具有改变的电化学氧化还原响应，这可以用于在 0.13 V 处测定各种巯基，与传统氧化还原介体相比，氧化电位降低很多，线性响应范围、响应斜率和检测限（LOD）相似。这项工作提出了一种表面工程方法，使用具有特定形态的银纳米颗粒设计和开发电化学氧化还原探针，表明羰基与银纳米颗粒之间的相互作用可能会扩展到表面增强拉曼散射以外的传感应用。
