Desenvolvimento de um biossensor para determinação de Bisfenol A

• Autor(a) principal: Silva, Mariana Sousa Prata Monteiro da
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.22/15106
• topic: Bisphenol A; Laccase; Biosensor; Screen-printed carbon electrodes; Ionic liquid; Multi-Walled Carbon Nanotubes; Bisfenol A; Biossensor; Elétrodos de carbono serigrafados; Líquido iónico; Nanotubos de carbono com paredes múltiplas; Lacase

The exposure to bisphenol A (BPA), a contaminant of emerging concern, is an environmental and public health problem; recently, it has been detected in a variety of daily products. Therefore, it is urgent to develop fast, simple, low cost, and portable determination techniques in order to assess the contamination by this chemical compound. Thus, the main objective of this study was the development of a biosensor based on laccase from Trametes versicolor to determine BPA. For that purpose, an electrochemical biosensor was developed using a screen-printed carbon electrode modified by the drop coating technique. The modification strategy consisted of two sequential phases: first, multi-walled carbon nanotubes were deposited onto the electrode surface, and once this film was dried, a composite composed by laccase (12.4 mg mL-1), the ionic liquid 1-butyl-3-methyl imidazolium tetrafluoroborate and chitosan (5 mg mL1 ) in an optimum proportion of 5:2:3 (v/v/v) was drop-casted onto the previously modified surface. Cyclic and square-wave voltammetry were used for characterization of the biosensor construction and BPA electroanalysis. The developed enzymatic biosensor exhibited satisfactory electroanalytical performance with a sensitivity of (6.36 ± 0.09)  10-2 µA/µM, linearity range of 0.5 – 8 µM, a limit of detection of 6.9 nM, relative standard deviation values of ca. 4.3% in the reproducibility assays and recoveries of 94.6 ± 5.0% in environmental waters. The proposed biosensor has the potential to be a useful device for BPA assessment.