Department of Biomedical Engineering, Binghamton University, Binghamton, NY, 13902, USA.
Office of the Vice President for Research, University of Rhode Island, Kingston, RI, 02881, USA.
Sci Rep. 2017 Jul 26;7(1):6631. doi: 10.1038/s41598-017-06884-8.
We report on ultraviolet (UV) light induced increases in the UV optical density of thin and optically transparent crystalline DNA films formed through self assembly. The films are comprised of closely packed, multi-faceted and sub micron sized crystals. UV-Vis spectrophotometry reveals that DNA films with surface densities up to 0.031 mg/mm can reduce the transmittance of incident UVC and UVB light by up to 90%, and UVA transmittance by up to 20%. Subsequent and independent film irradiation with either UVA or UVB dosages upwards of 80 J/cm both reduce UV transmittance, with reductions scaling monotonically with UV dosage. To date the induction of a hyperchromic effect has been demonstrated using heat, pH, high salt mediums, and high energy ionising radiation. Both hyperchromicity and increased light scattering could account for the increased film optical density after UV irradiation. Additional characterisation of the films reveal they are highly absorbent and hygroscopic. When coated on human skin, they are capable of slowing water evaporation and keeping the tissue hydrated for extended periods of time.
我们报告了在紫外（UV）光照射下，通过自组装形成的薄的、光学透明的结晶 DNA 薄膜的 UV 光密度增加。这些薄膜由紧密堆积的、多面的和亚微米大小的晶体组成。紫外可见分光光度法显示，表面密度高达 0.031mg/mm 的 DNA 薄膜可以将入射的 UVC 和 UVB 光的透射率降低多达 90%，并将 UVA 透射率降低多达 20%。随后，用 UVA 或 UVB 剂量对薄膜进行独立照射，剂量高达 80J/cm2 以上，均可降低 UV 透射率，降低幅度与 UV 剂量呈单调递增关系。迄今为止，已经证明热、pH 值、高盐介质和高能电离辐射可以诱导产生高色效应。在 UV 照射后，高色效应和光散射的增加都可能导致薄膜光学密度的增加。对薄膜的进一步表征表明，它们具有很强的吸水性和吸湿性。当涂在人体皮肤上时，它们能够减缓水分蒸发，使组织长时间保持湿润。
