A fibre-optic immunosensor for 2,4-dichlorophenoxyacetic acid detection

Lucia Mosiello, Luca Nencini, Lia Segre, Marcello Spanò

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A new total internal reflection fluorescence (TIRF) fibre-optic sensor working with the red fluorophore Cy5 and based on a compact, inexpensive solid-state laser source and photodetector is presented. The sensor has been tested with a monoclonal antibody (mAb) developed in our laboratory against the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The perfomances of mAb- and hapten-coated fibres are compared. A detection threshold below 60 pM is achieved with the latter configuration, with mAb as the analyte. An immunoassay for 2,4-D in solution has also been developed and compared with an analogous immunoenzymatic assay (ELISA). The TIRF assay allowed the mAb equilibrium dissociation constant for the liquid-phase antibody-antigen reaction to be calculated.
Original languageEnglish
Pages (from-to)353 - 359
Number of pages7
JournalSensors and Actuators, B: Chemical
Issue number1-3
Publication statusPublished - 1997
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry

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