Monoclonal antibody-gold biosensor chips for detection of depurinating carcinogen-DNA adducts by fluorescence line-narrowing spectroscopy

Scott D. Duhachek, Jeremy R. Kenseth, George P. Casale, Gerald J. Small, Marc D. Porter, Ryszard Jankowiak

Research output: Contribution to journalArticle

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Abstract

A new direct readout methodology for detection and quantitation of fluorescent carcinogen-DNA adducts is described. It combines the binding specificity of an immobilized monoclonal antibody (MAb) with high-resolution, low-temperature fluorescence spectroscopy. The MAb, which is covalently bound to a gold surface via a chemisorbed disulfide coupling agent, binds the adduct of interest in an aqueous sample. Laser-induced fluorescence under nonline narrowing (FNLN) and line-narrowing (FLN) conditions was used to detect (benzo[a]pyren-6-yl)guanine (BP-6-N7Gua) bound to immobilized MAb. At room temperature, the BP-6-N7Gua fluorescence was not detected, most likely because of quenching by the gold surface and/or efficient dynamical quenching. However, fluorescence was observed at room temperature when the surface was covered with a thin layer of glycerol, and possible reasons for the fluorescence enhancement are considered. Lowering of the temperature to 77 K led to nearly an order of magnitude increase in fluorescence intensity. Highly structured FLN spectra obtained at 4.2 K allowed for definitive adduct identification. The potential of this methodology for risk assessments of individuals exposed to polycyclic aromatic hydrocarbons is discussed.

Original languageEnglish (US)
Pages (from-to)3709-3716
Number of pages8
JournalAnalytical chemistry
Volume72
Issue number16
DOIs
StatePublished - Aug 15 2000

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ASJC Scopus subject areas

  • Analytical Chemistry

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