Étude comparative de l'adsorption d'acide déoxyribonucléique sur le chrysotile et le chrysotile phosphorylé (chrysophosphate)

Deoxyribonucleic acid (DNA) adsorption on one sample of Canadian chrysotile and two samples of chrysophosphate has been studied using chemical analysis and a surface method of analysis (photoelectron spectroscopy, XPS). Chrysophosphate was obtained using a phosphorylation process applied to chrysotile fibres; one chrysophosphate sample was opened in a Pallmann device. XPS analysis of the samples before DNA adsorption has shown that some surface phosphorus was dissolved following suspension of the fibres in distilled water. After DNA treatment, the amount of DNA adsorbed at the surface of the chrysophosphate sample was lower than that adsorbed at the chrysotile surface (12.6 ± 1.7 μg/mg and 74.0 ± 4.0 μg/mg respectively). In addition, the opened sample adsorbed an intermediary DNA amount (28.3 ± 5.6 μg/mg), suggesting that the phosphorylation process has not reached all the bulk fibres. The results indicate that DNA adsorption is a sensitive method for investigation of the surface state of the fibre. Moreover, it seems that the phosphorylation process masks or blocks the reactive surface sites for DNA adsorption.