Label-free aptasensor for lysozyme detection using electrochemical impedance spectroscopy

This research develops a label-free aptamer biosensor (aptasensor) based on graphite-epoxy composite electrodes (GECs) for the detection of lysozyme protein using Electrochemical Impedance Spectroscopy (EIS) technique. The chosen immobilization technique was based on covalent bonding using carbodiim...

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Detalhes bibliográficos
Autores: Ortiz, Dionisia|||0000-0002-5637-8120, Valle, Manel del|||0000-0002-1032-8611
Formato: artículo
Fecha de publicación:2018
País:España
Recursos:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:199392
Acesso em linha:https://ddd.uab.cat/record/199392
https://dx.doi.org/urn:doi:10.3390/s18020354
Access Level:acceso abierto
Palavra-chave:Aptamer
Biosensor
Electrochemical grafting
Electrochemical impedance spectroscopy
Descrição
Resumo:This research develops a label-free aptamer biosensor (aptasensor) based on graphite-epoxy composite electrodes (GECs) for the detection of lysozyme protein using Electrochemical Impedance Spectroscopy (EIS) technique. The chosen immobilization technique was based on covalent bonding using carbodiimide chemistry; for this purpose, carboxylic moieties were first generated on the graphite by electrochemical grafting. The detection was performed using [Fe(CN)]/[Fe(CN)] as redox probe. After recording the frequency response, values were fitted to its electric model using the principle of equivalent circuits. The aptasensor showed a linear response up to 5 µMfor lysozyme and a limit of detection of 1.67 µM. The sensitivity of the established method was 0.090 µM in relative charge transfer resistance values. The interference response by main proteins, such as bovine serum albumin and cytochrome c, has been also characterized. To finally verify the performance of the developed aptasensor, it was applied to wine analysis.