Enhanced electrochemical detection of nonelectroactive compounds based on surface supramolecular interactions on chevron-like graphene nanoribbons modified through click chemistry
In this study, we have developed a nanostructured electrochemical sensor based on modified graphene nanoribbons tailored for the analysis of nonelectroactive compounds via a surface competitive assay. Stigmasterol, a nonelectroactive phytosterol, was selected as a representative case. Chevron-like g...
| Autores: | , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.uam.es:10486/720141 |
| Acceso en línea: | http://hdl.handle.net/10486/720141 https://dx.doi.org/10.1021/acsomega.4c06639 |
| Access Level: | acceso abierto |
| Palabra clave: | Grafting (chemical) liquid film X-Ray photoelectron spectroscopy Química |
| Sumario: | In this study, we have developed a nanostructured electrochemical sensor based on modified graphene nanoribbons tailored for the analysis of nonelectroactive compounds via a surface competitive assay. Stigmasterol, a nonelectroactive phytosterol, was selected as a representative case. Chevron-like graphene nanoribbons, chemically synthesized, were immobilized onto glassy carbon electrodes and covalently functionalized to allow the on-surface formation of a supramolecular complex. To this end, the nanoribbons were first modified through a diazotization process by electrochemical reduction of a 4-azidoaniline diazonium salt, leaving the electrode surface with azide groups exposed to solution. Next, the incorporation of a ferrocene group, as a redox probe, was carried out by a click chemistry reaction between ethynylferrocene and these azide groups. Finally, the recognition event leads to the formation of a supramolecular complex between ferrocene and a macrocyclic receptor on the electrode surface. To this end, the receptors cucurbit[7]uril, cucurbit[8]uril, and β-cyclodextrin were evaluated, with the better results obtained with β-cyclodextrin. Atomic force microscopy and scanning electron microscopy measurements were performed for the morphological characterization of the resulting electrochemical platform surface. The ability of β-cyclodextrin to form an inclusion complex with ferrocene or with stigmasterol allows to perform a competitive assay, which translates into the decrease and recovery of the ferrocene electrochemical signal. For stigmasterol determination, a linear concentration range between 200 and 750 μM and a detection limit of 60 μM were obtained, with relative errors and relative standard deviations less than 7.1 and 9.8%, respectively |
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