Publication details
The immunosensors for measurement of 2,4-dichlorophenoxyacetic acid based on electrochemical impedance spectroscopy
| Authors | |
|---|---|
| Year of publication | 2004 |
| Type | Article in Periodical |
| Magazine / Source | Bioelectrochemistry |
| MU Faculty or unit | |
| Citation | |
| Field | Biochemistry |
| Keywords | Impedance; Immunosensor; Herbicide |
| Description | Electrochemical impedance spectroscopy was evaluated for the direct determination of herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Specific antibody against 2,4-D was immobilised onto different gold electrodes. Several methods of antibody immobilisation by covalent linkage to modified surface were studied. Self-assembled monolayers formed using thiocompounds as cystamine, 4-aminothiophenol (ATPh), 3,3'-dithiopropionic acid di(N-succinimidyl ester) (DTSP) and 11-mercaptoundecanoic acid (MUA) were chosen for the sensing surface activation. Three different sensor types were tested: screen-printed disc and finger-like structures and interdigitated array (IDA) electrodes produced by lithography. The measurements were carried out in a stationary arrangement and the reaction between hapten and the immobilised antibody was observed on-line. Changes of impedance parameters were evaluated and the best immobilisation technique (using 4-aminothiophenol) was chosen for further measurements. Impedance changes due to immunocomplex formation were evaluated and the possibility of direct monitoring of 2,4-D binding to the antibody was demonstrated at a fixed frequency. |
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