Enzymeless glucose sensor based on disposable Ecoflex®/graphite thermoplastic composite substrate modified with Au@GQDs
There is an increasing demand for robust, affordable, and sensitive analytical devices for clinical diagnostics. Herein, we describe a simple route to produce biodegradable and disposable thermoplastic composite electrodes using the commercial polymer (Ecoflex®) and graphite microparticles. The surf...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2022 |
| País: | Brasil |
| Institución: | Universidade Estadual Paulista (UNESP) |
| Repositorio: | Repositório Institucional da UNESP |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unesp.br:11449/241651 |
| Acceso en línea: | http://dx.doi.org/10.1016/j.snr.2022.100102 http://hdl.handle.net/11449/241651 |
| Access Level: | acceso abierto |
| Palabra clave: | Biodegradable material Enzyme-free sensor Glucose detection Low-cost electrochemical sensor Thermoplastic composite electrodes |
| Sumario: | There is an increasing demand for robust, affordable, and sensitive analytical devices for clinical diagnostics. Herein, we describe a simple route to produce biodegradable and disposable thermoplastic composite electrodes using the commercial polymer (Ecoflex®) and graphite microparticles. The surface of the carbon composite electrode was modified with gold nanoparticles conjugated with graphene quantum dots (Au@GQDs) for sensitive and non-enzymatic glucose sensing. The morphological and structural characterizations of the modified electrochemical device revealed a hydrophilic rough composite surface, with high dispersion of graphite in the polymer matrix and confirmed the successful superficial modification of the working electrode with spherical Au@GQDs nanoparticles. Cyclic voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were used to electrochemically characterize the modified and nonmodified thermoplastic sensor, demonstrating a 4.5-fold enhancement of the electroactive area, higher heterogeneous electron transfer kinetics, and electrocatalytic properties for glucose sensing when the sensor was modified with Au@GQDs. The electrochemical determination of the glucose was carried out using an amperometric method applying -0.15 V in alkaline conditions (0.1 mol L−1 NaOH). Under optimized conditions, the proposed method presented a high sensitivity (4.85 A L mol−1) and a low limit of detection (LOD) of 9.12 µmol L−1. The Ecoflex:graphite/Au@GQDs sensor was applied for glucose sensing in synthetic saliva samples with recovery values ranging from 97.84% to 105.20%, highlighting the excellent accuracy of the proposed method. Finally, the electrode was subjected to thermal and biological degradation studies and presented disposable and eco-friendly characteristics. Based on these results, we believe that this new thermoplastic composite sensor modified with Au@GQDs can be an excellent candidate for a disposable, low-cost, and enzymeless electrochemical glucose sensor. |
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