Modulating the Geometry of the Carbon Nanofiber Electrodes Provides Control over Dopamine Sensor Performance

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Analytical Chemistry
One of the major challenges for in vivo electrochemical measurements of dopamine (DA) is to achieve selectivity in the presence of interferents, such as ascorbic acid (AA) and uric acid (UA). Complicated multimaterial structures and ill-defined pretreatments have been frequently utilized to enhance selectivity. The lack of control over the realized structures has prevented establishing associations between the achieved selectivity and the electrode structure. Owing to their easily tailorable structure, carbon nanofiber (CNF) electrodes have become promising materials for neurobiological applications. Here, a novel yet simple strategy to control the sensitivity and selectivity of CNF electrodes toward DA is reported. It consists of adjusting the lengths of CNF by modulating the growth phase during the fabrication process while keeping the surface chemistries similar. It was observed that the sensitivity of the CNF electrodes toward DA was enhanced with the increase in the fiber lengths. More importantly, the increase in the fiber length induced (i) an anodic shift in the DA oxidation peak and (ii) a cathodic shift in the AA oxidation peak. As the UA oxidation peak remained unaffected at high anodic potentials, the electrodes with long CNFs showed excellent selectivity. Electrodes without proper fibers showed only a single broad peak in the solution of AA, DA, and UA, completely lacking the ability to discriminate DA. Hence, the simple strategy of controlling CNF length without the need to carry out any complex chemical treatments provides us a feasible and robust route to fabricate electrode materials for neurotransmitter detection with excellent sensitivity and selectivity.
Funding Information: T.L. acknowledges funding by European Union’s Horizon 2020 research and innovation program H2020-FETPROACT-636 2018-01 (Grant 824070). E.P. acknowledges funding from the Academy of Finland (Grants 321996 and 328854) and Jane and Aatos Erkko Foundation. The authors acknowledge the provision of facilities and technical support by Aalto University at OtaNano─Nanomicroscopy Center (Aalto-NMC) and at Micronova Nanofabrication Centre. Publisher Copyright: © 2023 The Authors. Published by American Chemical Society. | openaire: EC/H2020/824070/EU//CONNECT
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Kousar, A, Pande, I, Ferrer Pascual, L, Peltola, E, Sainio, J & Laurila, T 2023, ' Modulating the Geometry of the Carbon Nanofiber Electrodes Provides Control over Dopamine Sensor Performance ', Analytical Chemistry, vol. 95, no. 5, pp. 2983-2991 .