Resum
© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. An impedimetric transducer based on an interdigitated electrode array (IDEA) modified with polyethyleneimine was used to study interactions with bacteria present in a sample solution. Bacteria immobilization on the sensor surface affects the surface charge and produces changes in the superficial impedance. The sensor surface was chemically modified by layer-by-layer (LbL) method with oppositely charged polyelectrolyte layers by alternating polyethyleneimine (PEI) and poly(sodium 4-styrenesulfonate) (PSS). Escherichia coli gram-negative bacteria were employed as a model for sensitivity and response time evaluation. Bacteria were immobilized on IDEA with PEI-PSS-PEI multilayer taking into account the ability of PEI to react chemically with outer membrane compounds of gram-negative bacteria and thus improve purely electrostatic interactions. Detection limit of the sensor was found to be as low as 101cfu/mL in E. coli cultures with response time around 20minutes. In order to introduce a biorecognition element by bacterial detection, the lectin Concanavalin A (ConA) was deposited on IDEA surface through PEI-ConA interaction, achieving a detection limit of 104cfu/mL. The strategies developed show the possibility to achieve highly sensitive and rapid detection of bacteria using IDEA transducers.
Idioma original | Anglès |
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Pàgines (de-a) | 656-662 |
Revista | Electroanalysis |
Volum | 27 |
Número | 3 |
DOIs | |
Estat de la publicació | Publicada - 1 de gen. 2015 |