Abstract
We report herein a simple and effective way to photochemically immobilize biomolecules onto a fibre-optic silica surface. The system is based on a photoreactive benzophenone derivative that is bound to SiO2 surfaces of the optical fibre via a silane anchor. The benzophenone derivative was 4-allyloxybenzophenone, synthesized by standard procedures that were later used to synthesize the 4-(3′-chlorodimethylsilyl) propyloxybenzophenone and 4-(3′-dichloromethylsilyl) propyloxybenzophenone by regular hydrosilation procedures. After silanization with the benzophenone derivatives, the fibres were immersed in a cholera toxin B subunit solution and illuminated with UV light (wavelength > 345 nm). As a result of the photochemical reaction, a thin layer of the antigen was covalently bound to the benzophenone-modified surface. The photochemically modified fibre-optics were then tested as immunosensors in the detection of cholera anti-toxin antibody and revealed through chemiluminescence measurements. A secondary antibody labelled with horseradish peroxidase acted as the marker for the cholera toxin antibody. A photo-electronic set-up was designed specifically to monitor the signal. The immunosensor system was shown to be both specific and sensitive. The lowest rabbit serum titre detected was 1:1 700 000.
Original language | English |
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Pages (from-to) | 69-77 |
Number of pages | 9 |
Journal | Luminescence |
Volume | 19 |
Issue number | 2 |
DOIs | |
State | Published - 1 Jan 2004 |
Keywords
- Chemiluminescence
- Cholera diagnostics
- Fibre-optic immunosensor
- Protein immobilization
- Silane-benzophenone
ASJC Scopus subject areas
- Biophysics
- Chemistry (miscellaneous)