A capacitive immunosensor for detection of cholera toxin

Mahmoud Labib; Martin Hedström; Magdy Amin; Bo Mattiasson

doi:10.1016/j.aca.2008.12.035

A capacitive immunosensor for detection of cholera toxin

Mahmoud Labib, Martin Hedström, Magdy Amin, Bo Mattiasson^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

61 Scopus citations

Abstract

Contamination of food with biological toxins as well as their potential use as weapons of mass destruction has created an urge for rapid and cost effective analytical techniques capable of detecting trace amounts of these toxins. This paper describes the development of a sensitive method for detection of cholera toxin (CT) using a flow-injection capacitive immunosensor based on self-assembled monolayers. The sensing surface consists of monoclonal antibodies against the B subunit of CT (anti-CT), immobilized on a gold transducer. Experimental results show that the immunosensor responded linearly to CT concentrations in the range from 1.0 × 10^-13 to 1.0 × 10^-10 M under optimized conditions. The limit of detection (LOD) was 1.0 × 10^-14 M. Two more analytical methods were employed for detection of CT using the same antibody namely, sandwich ELISA and surface plasmon resonance (SPR)-based immunosensor. The former had an LOD of 1.2 × 10^-12 M and a working range from 3.7 × 10^-11 to 2.9 × 10^-10 M whereas, the later had an LOD of 1.0 × 10^-11 M and a linearity ranging from 1.0 × 10^-9 to 1.0 × 10^-6 M. These results demonstrate that the developed capacitive immunosensor system has a higher sensitivity than the other two techniques. The binding affinity of CT to the immobilized anti-CT was determined using the SPR-based immunosensor and an association constant (K_A) of 1.4 × 10⁹ M^-1 was estimated.

Original language	English (US)
Pages (from-to)	255-261
Number of pages	7
Journal	Analytica Chimica Acta
Volume	634
Issue number	2
DOIs	https://doi.org/10.1016/j.aca.2008.12.035
State	Published - Feb 23 2009
Externally published	Yes

Funding

Ministry of Higher Education, Egypt is gratefully acknowledged for financial support to Mahmoud Labib during his study at the Department of Biotechnology, Lund University. The authors express their gratitude to Professor Ann-Mari Svennerholm, Department of Microbiology and Immunology, Göteborg University for her keen interest, providing them with the anti-CT used in this work and Dr. Bengt Danielsson, Department of Pure and Applied Biochemistry, Lund University for access to their instruments and helpful discussions.

Keywords

Capacitive immunosensor
Cholera toxin
Enzyme-linked immunosorbent assays
Surface plasmon resonance

ASJC Scopus subject areas

Analytical Chemistry
Biochemistry
Spectroscopy
Environmental Chemistry

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1016/j.aca.2008.12.035

Cite this

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title = "A capacitive immunosensor for detection of cholera toxin",

abstract = "Contamination of food with biological toxins as well as their potential use as weapons of mass destruction has created an urge for rapid and cost effective analytical techniques capable of detecting trace amounts of these toxins. This paper describes the development of a sensitive method for detection of cholera toxin (CT) using a flow-injection capacitive immunosensor based on self-assembled monolayers. The sensing surface consists of monoclonal antibodies against the B subunit of CT (anti-CT), immobilized on a gold transducer. Experimental results show that the immunosensor responded linearly to CT concentrations in the range from 1.0 × 10-13 to 1.0 × 10-10 M under optimized conditions. The limit of detection (LOD) was 1.0 × 10-14 M. Two more analytical methods were employed for detection of CT using the same antibody namely, sandwich ELISA and surface plasmon resonance (SPR)-based immunosensor. The former had an LOD of 1.2 × 10-12 M and a working range from 3.7 × 10-11 to 2.9 × 10-10 M whereas, the later had an LOD of 1.0 × 10-11 M and a linearity ranging from 1.0 × 10-9 to 1.0 × 10-6 M. These results demonstrate that the developed capacitive immunosensor system has a higher sensitivity than the other two techniques. The binding affinity of CT to the immobilized anti-CT was determined using the SPR-based immunosensor and an association constant (KA) of 1.4 × 109 M-1 was estimated.",

keywords = "Capacitive immunosensor, Cholera toxin, Enzyme-linked immunosorbent assays, Surface plasmon resonance",

author = "Mahmoud Labib and Martin Hedstr{\"o}m and Magdy Amin and Bo Mattiasson",

note = "Funding Information: Ministry of Higher Education, Egypt is gratefully acknowledged for financial support to Mahmoud Labib during his study at the Department of Biotechnology, Lund University. The authors express their gratitude to Professor Ann-Mari Svennerholm, Department of Microbiology and Immunology, G{\"o}teborg University for her keen interest, providing them with the anti-CT used in this work and Dr. Bengt Danielsson, Department of Pure and Applied Biochemistry, Lund University for access to their instruments and helpful discussions.",

year = "2009",

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doi = "10.1016/j.aca.2008.12.035",

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AU - Labib, Mahmoud

AU - Hedström, Martin

AU - Amin, Magdy

AU - Mattiasson, Bo

N1 - Funding Information: Ministry of Higher Education, Egypt is gratefully acknowledged for financial support to Mahmoud Labib during his study at the Department of Biotechnology, Lund University. The authors express their gratitude to Professor Ann-Mari Svennerholm, Department of Microbiology and Immunology, Göteborg University for her keen interest, providing them with the anti-CT used in this work and Dr. Bengt Danielsson, Department of Pure and Applied Biochemistry, Lund University for access to their instruments and helpful discussions.

PY - 2009/2/23

Y1 - 2009/2/23

N2 - Contamination of food with biological toxins as well as their potential use as weapons of mass destruction has created an urge for rapid and cost effective analytical techniques capable of detecting trace amounts of these toxins. This paper describes the development of a sensitive method for detection of cholera toxin (CT) using a flow-injection capacitive immunosensor based on self-assembled monolayers. The sensing surface consists of monoclonal antibodies against the B subunit of CT (anti-CT), immobilized on a gold transducer. Experimental results show that the immunosensor responded linearly to CT concentrations in the range from 1.0 × 10-13 to 1.0 × 10-10 M under optimized conditions. The limit of detection (LOD) was 1.0 × 10-14 M. Two more analytical methods were employed for detection of CT using the same antibody namely, sandwich ELISA and surface plasmon resonance (SPR)-based immunosensor. The former had an LOD of 1.2 × 10-12 M and a working range from 3.7 × 10-11 to 2.9 × 10-10 M whereas, the later had an LOD of 1.0 × 10-11 M and a linearity ranging from 1.0 × 10-9 to 1.0 × 10-6 M. These results demonstrate that the developed capacitive immunosensor system has a higher sensitivity than the other two techniques. The binding affinity of CT to the immobilized anti-CT was determined using the SPR-based immunosensor and an association constant (KA) of 1.4 × 109 M-1 was estimated.

AB - Contamination of food with biological toxins as well as their potential use as weapons of mass destruction has created an urge for rapid and cost effective analytical techniques capable of detecting trace amounts of these toxins. This paper describes the development of a sensitive method for detection of cholera toxin (CT) using a flow-injection capacitive immunosensor based on self-assembled monolayers. The sensing surface consists of monoclonal antibodies against the B subunit of CT (anti-CT), immobilized on a gold transducer. Experimental results show that the immunosensor responded linearly to CT concentrations in the range from 1.0 × 10-13 to 1.0 × 10-10 M under optimized conditions. The limit of detection (LOD) was 1.0 × 10-14 M. Two more analytical methods were employed for detection of CT using the same antibody namely, sandwich ELISA and surface plasmon resonance (SPR)-based immunosensor. The former had an LOD of 1.2 × 10-12 M and a working range from 3.7 × 10-11 to 2.9 × 10-10 M whereas, the later had an LOD of 1.0 × 10-11 M and a linearity ranging from 1.0 × 10-9 to 1.0 × 10-6 M. These results demonstrate that the developed capacitive immunosensor system has a higher sensitivity than the other two techniques. The binding affinity of CT to the immobilized anti-CT was determined using the SPR-based immunosensor and an association constant (KA) of 1.4 × 109 M-1 was estimated.

KW - Capacitive immunosensor

KW - Cholera toxin

KW - Enzyme-linked immunosorbent assays

KW - Surface plasmon resonance

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ER -

A capacitive immunosensor for detection of cholera toxin

Abstract

Funding

Keywords

ASJC Scopus subject areas

UN SDGs

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