Carbon quantum dot coated Fe3O4 hybrid composites for sensitive electrochemical detection of uric acid

Autor: Keith R Hallam, Mehvish Zahoor, Erol Pehlivan, Ahmet Avci, Nazar Hussain Kalwar, Razium Ali Soomro, Malik Waseem Abbas, Magnus Willander
Rok vydání: 2019
Předmět:
Zdroj: Microchemical Journal. 146:517-524
ISSN: 0026-265X
DOI: 10.1016/j.microc.2019.01.034
Popis: The study explores carbon quantum dots (C-dots) as potential candidates for enhancing the signal sensitivity of an electrochemical sensor devised for biologically important molecule, such as uric acid (UA). The C-dots were evaluated for their electrochemical characteristics in combination with Fe3O4 nanoparticles (Fe3O4 NPs), which were applied as the primary electro-catalytic promoter. The hybrid nanocomposite (C-dots/Fe3O4 HCs) formation was achieved by facilitating the adsorption of C-dots over Fe3O4 NPs using amine-carbonyl interactions. Unlike, one pot method, the proposed strategy enables aggregation-free coverage of Fe3O4 NPs with highly conductive layer of C-dots that can act as conduction centres to support ultra-fast electron transfer kinetics to satisfy the need of high signal sensitivity. The hybrid composite demonstrated remarkable signal improvement when tested against the electrochemical oxidation of UA. The heighten current response and lower over-potential values enabled development of a DC-amperometric (DC-AMP) sensor for UA with a linear working range of 0.01 to 0.145 μM and signal sensitivity measurable up to 6.0 × 10−9 M. The said improvement was manifested as a synergetic outcome of active redox couple (Fe (III/II)), larger surface area of Fe3O4 NPs engulfed with a layer of highly conductive C-dots acting as efficient charge sensitisers.
Databáze: OpenAIRE
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