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Sub-attomolar detection of cholera toxin using a label-free capacitive immunosensor

Loyprasert, S. ; Hedström, Martin LU ; Thavarungkul, P. ; Kanatharana, P. and Mattiasson, Bo LU (2010) In Biosensors & Bioelectronics 25(8). p.1977-1983
Abstract
A label-free immunosensor for the direct detection of cholera toxin (CT) at sub-attomolar level has been developed based on potential-step capacitance measurements. Anti-CT antibody was adsorbed on gold nanoparticles (AuNPs) incorporated on a polytyramine-modified gold electrode. The concentration of CT was determined by detecting the change of capacitance caused by the formation of antibody-antigen complexes. By using AuNPs adsorbed to the sensing surface, the signal was dramatically increased leading to a significantly more sensitive assay. In fact, under optimum conditions the immunosensor could detect CT concentration with a limit of detection of 9 x 10(-20) M or 0.09 aM, with a dynamic range between 0.1 aM and 10 pM. Good analytical... (More)
A label-free immunosensor for the direct detection of cholera toxin (CT) at sub-attomolar level has been developed based on potential-step capacitance measurements. Anti-CT antibody was adsorbed on gold nanoparticles (AuNPs) incorporated on a polytyramine-modified gold electrode. The concentration of CT was determined by detecting the change of capacitance caused by the formation of antibody-antigen complexes. By using AuNPs adsorbed to the sensing surface, the signal was dramatically increased leading to a significantly more sensitive assay. In fact, under optimum conditions the immunosensor could detect CT concentration with a limit of detection of 9 x 10(-20) M or 0.09 aM, with a dynamic range between 0.1 aM and 10 pM. Good analytical reproducibility could be obtained by injecting CT up to 36 times with an RSD of 2.5%. In addition, good performance of the developed immunosensor was achieved when applied to turbid water samples collected from a local stream that were spiked with CT. (c) 2010 Elsevier B.V. All rights reserved. (Less)
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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Cholera toxin, AuNPs, Label-free immunosensor, Attomolar, Capacitance
in
Biosensors & Bioelectronics
volume
25
issue
8
pages
1977 - 1983
publisher
Elsevier
external identifiers
  • wos:000276424200019
  • scopus:77649184818
  • pmid:20167466
ISSN
1873-4235
DOI
10.1016/j.bios.2010.01.020
language
English
LU publication?
yes
id
5691be0e-9627-4901-b60c-ea7baff2c019 (old id 1603969)
date added to LUP
2016-04-01 13:25:14
date last changed
2022-01-27 19:08:33
@article{5691be0e-9627-4901-b60c-ea7baff2c019,
  abstract     = {{A label-free immunosensor for the direct detection of cholera toxin (CT) at sub-attomolar level has been developed based on potential-step capacitance measurements. Anti-CT antibody was adsorbed on gold nanoparticles (AuNPs) incorporated on a polytyramine-modified gold electrode. The concentration of CT was determined by detecting the change of capacitance caused by the formation of antibody-antigen complexes. By using AuNPs adsorbed to the sensing surface, the signal was dramatically increased leading to a significantly more sensitive assay. In fact, under optimum conditions the immunosensor could detect CT concentration with a limit of detection of 9 x 10(-20) M or 0.09 aM, with a dynamic range between 0.1 aM and 10 pM. Good analytical reproducibility could be obtained by injecting CT up to 36 times with an RSD of 2.5%. In addition, good performance of the developed immunosensor was achieved when applied to turbid water samples collected from a local stream that were spiked with CT. (c) 2010 Elsevier B.V. All rights reserved.}},
  author       = {{Loyprasert, S. and Hedström, Martin and Thavarungkul, P. and Kanatharana, P. and Mattiasson, Bo}},
  issn         = {{1873-4235}},
  keywords     = {{Cholera toxin; AuNPs; Label-free immunosensor; Attomolar; Capacitance}},
  language     = {{eng}},
  number       = {{8}},
  pages        = {{1977--1983}},
  publisher    = {{Elsevier}},
  series       = {{Biosensors & Bioelectronics}},
  title        = {{Sub-attomolar detection of cholera toxin using a label-free capacitive immunosensor}},
  url          = {{http://dx.doi.org/10.1016/j.bios.2010.01.020}},
  doi          = {{10.1016/j.bios.2010.01.020}},
  volume       = {{25}},
  year         = {{2010}},
}