Solid-Matrix Fluorescence and Phosphorescence Detection and Characterization of Benzo[ a ]pyrene–DNA Adducts with Whatman No. 1 and Whatman 1PS Filter Paper

Abstract

Benzo[a]pyrene (B[a]P) is a potential carcinogen and mutagen, and it has been studied very extensively. In humans, B[a]P can be metabolized and becomes chemically bonded to DNA. A variety of methods are needed for the characterization of B[a]P–DNA adducts because of the structural complexity of the adducts. In this work, several solid-matrix luminescence methods were developed for the characterization of the B[a]P-DNA adducts. Both solid-matrix fluorescence and solid-matrix phosphorescence could be obtained from the adducts on Whatman No. 1 and Whatman 1PS filter paper at nanogram levels. Thallium nitrate proved to be an effective heavy atom in enhancing the solid-matrix phosphorescence of the adducts. By selective excitation of the phosphorescence of the adducts, it was possible to excite different forms of the adducts. With moisture quenching of the solid-matrix phosphorescence of the B[a]P-DNA adducts, it was feasible to selectively detect quasi-intercalated adducts. With Whatman 1PS filter paper, a unique method was developed for the solid-matrix fluorescence detection of adducts externally bound to DNA by the hydrophobic interaction of the adducts with the 1PS paper.