A layered nanocomposite of laccase, chitosan, and Fe 3 O 4 nanoparticles-reduced graphene oxide for the nanomolar electr
- PDF / 613,516 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 8 Downloads / 210 Views
ORIGINAL PAPER
A layered nanocomposite of laccase, chitosan, and Fe3O4 nanoparticles-reduced graphene oxide for the nanomolar electrochemical detection of bisphenol A Paula M. V. Fernandes 1 & José M. Campiña 1
&
A. Fernando Silva 1
Received: 14 October 2019 / Accepted: 7 March 2020 # Springer-Verlag GmbH Austria, part of Springer Nature 2020
Abstract A hybrid conjugate of reduced graphene oxide/ferrous-ferric oxide nanoparticles (rGO-Fe3O4 NPs) is characterized and assembled with chitosan and laccase to form a layered functional superstructure. After its characterization by field-effect scanning electron microscopy, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS), the nanocomposite has been deposited on glassy carbon for the enzyme-mediated electrochemical determination of the endocrine disruptor bisphenol A (BPA). Proof-of-concept assays conducted by using CV, EIS, and square wave voltammetry reveal that the enzymatic biosensor provides linear response in a wide range of BPA concentrations (6–228 ppb), very high sensitivities, and excellent durability (over 1-month storage). Using amperometric detection, remarkable sensitivities (2080 μA μM−1 cm−2) and detection limits (18 nM) are attained. Applications to real samples of bottled water proved feasible with recoveries in the range 107–124%. Keywords Graphene nanomaterials . Graphene-nanoparticle conjugates . Magnetite nanoparticles . Enzymatic biosensors . FESEM . XPS . ATR-FTIR . Cyclic voltammetry . Square wave voltammetry . Electrochemical impedance spectroscopy . Chronoamperometry
Introduction The 2,2-bis(4-hydroxyphenyl)propane (aka bisphenol A or BPA) is one of the most ubiquitous endocrine disruptors (EDs). Its ability to bind intracellular estrogen receptors (ERα, ERβ, and ERRγ) even at minimal doses [1, 2] may induce reproductive dysfunctions, increase risks of cancer, etc. [3, 4]. BPA has been found in consumer items (plastic food trays and baby bottles, beverage cans, etc.) by solid-phase micro-extraction, gas/liquid chromatography-mass spectrometry, fluorescence spectroscopy, etc. [5–7]. However, other
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00604-020-4223-x) contains supplementary material, which is available to authorized users. * José M. Campiña [email protected] 1
Department of Chemistry and Biochemistry, Faculty of Sciences, Centre for Research in Chemistry of The University of Porto (CIQUP), Rua do Campo Alegre 687, 4169-007 Porto, Portugal
approaches based on miniaturized electroanalytical platforms seem more suitable for any environmental tracing of pollutants due to their low cost, reduced size, portability, high sensitivity, and rapid response. Reduced graphene oxides (rGO) exhibit well-balanced surface-to-volume ratio, electrical conductivity, and electrocatalytic activity to serve as conductivity/ charge transfer enhancer in nanostr
Data Loading...
