Dose effects in electron beam irradiation of DNA-complex thin films

摘要

Electron beam irradiation of double-stranded DNA (dsDNA)-surfactant thin films was investigated. Irradiation caused dissociation, leading to increasing thin film solubility in water and degradation of dsDNA. These two effects produced a maximum concentration of dsDNA in aqueous solution at 400 μC/cm2 dose. These properties resulted in dual-mode resist characteristics of the DNA-surfactant films. At low dose, the DNA films functioned as positive resist while at high dose they worked as negative resist. The transition between the two regimes also occurred at 400 μC/cm2. This implies that the cross-linking process (typical for negative resists) first requires the dissociation of the DNA-surfactant complex.