Probing antigen-antibody interactions on electrode supports by the biocatalyzed precipitation of an insoluble product

Amos Bardea, Eugenii Katz, Itamar Willner

Research output: Contribution to journalArticlepeer-review

86 Scopus citations

Abstract

The amplified sensing of an antibody by an antigen monolayer-functionalized transducer by using a biocatalyzed precipitation of an insoluble product on the transducer is addressed. Faradaic impedance spectroscopy, cyclic voltammetry and microgravimetric, quartz crystal microbalance analyses are used to probe the precipitation of the insoluble product on the transducer. A dinitrophenyl, DNP, antigen monolayer is assembled on a Au-electrode, or a Au-quartz crystal, as a sensing interface the dinitrophenyl-antibody, DNP-Ab. An anti-Fc-antibody-HRP conjugate is used as a biocatalytic probe for the formation of the antigen/DNP-Ab complex on the transducer. Biocatalyzed oxidation of 4-chloronaphthol by H2O2 in the presence of the anti-Fc-antibody-HRP conjugate yields an insoluble product on the transducer. Formation of the insoluble film on the electrode results in the increase of interfacial electron-transfer resistances detected by impedance spectroscopy or cyclic voltammetry. The precipitate formation also results in the mass increase of the modified Au-quartz crystal detected as a frequency change of the piezoelectric transducer. The DNP-Ab is easily sensed at a sensitivity that corresponds to 0.5 ng mL-1 (3 x 10-12 M).

Original languageEnglish
Pages (from-to)1097-1106
Number of pages10
JournalElectroanalysis
Volume12
Issue number14
DOIs
StatePublished - 2000
Externally publishedYes

Keywords

  • Bioelectronics
  • Biosensor
  • Immunosensor
  • Impedance spectroscopy, Quartz crystal microbalance
  • Monolayer

Fingerprint

Dive into the research topics of 'Probing antigen-antibody interactions on electrode supports by the biocatalyzed precipitation of an insoluble product'. Together they form a unique fingerprint.

Cite this