Exposure lateral flow strip sensitive detection of oxidative DNA damage induced by transition metal and organic compound

Investigation of rapid and sensitive method for detecting DNA damage is meaningful for screening the chemical compounds with potential genotoxicity and for earlier diagnosis of the related diseases. In this study, we reported a gold nanoparticle (AuNP) based exposure lateral flow strip (LFS) to determine oxidative DNA damage induced by two typical damaging reagents, including transition metal (Fenton reagents, Fe 2+ /H 2 O 2 ) and organic compounds (Rose Bengal under irradiation). The presence of human 8-oxoguanine DNA glycosylase (HOGG 1) and human apyrimidinic endonuclease (APE 1) converted the oxidized base, 8-oxo-7,8-dihydro-2′-deoxyguanosine (denoted as 8-oxodGuo, one of the major products of oxidative damage DNA), to strand break in a hairpin DNA probe. The opened loop acted as a linker to anchor the AuNP@DNA complexes on the test line (T-line). The visible red color appearing on the T-line was analyzed by employing Image J software for digital image acquisition, enabling quantification of DNA lesions with the measured mean grey value. Quantification of 8-oxodGuo was achieved with an estimated detection limit down to 0.003 pmol. About 67-fold more sensitive than the previously reported elimination LFS is mainly ascribed to the specific hairpin DNA structure to capture the signal probe complex and the exposure LFS signal readout. Furthermore, oxidatively generated DNA damage by Rose Bengal or Fe 2+ /H 2 O 2 were then assessed. The proposed exposure LFS detected as low as 2 nM of Rose Bengal or 0.06 nM Fe 2+ /0.24 nM H 2 O 2 produced DNA lesions, respectively. It shows the potential to serve as a screening tool for rapidly acquiring toxicological data on emerging chemicals.