Qin Tian, Gutu Timothy, Jiao Jun, Chang Chih-Hung, Rorrer Gregory L
Department of Chemical Engineering, Oregon State University, Corvallis, Oregon 97331, USA.
ACS Nano. 2008 Jun;2(6):1296-304. doi: 10.1021/nn800114q.
Diatoms are single-celled algae that make microscale silica shells or "frustules" with intricate nanoscale features such as two-dimensional pore arrays. In this study, the metabolic insertion of low levels of germanium into the frustule biosilica of the pennate diatom Nitzschia frustulum by a two-stage cultivation process induced the formation of frustules which strongly resembled double-sided nanocomb structures. The final product from the two-stage cultivation process contained 0.41 wt % Ge in biosilica and consisted of an equal mixture of parent frustule valves possessing a normal two-dimensional array of 200 nm pores and daughter valves possessing the nanocomb structure. The nanocomb structures had overall length of 8 mum, rib width of 200 nm, rib length of 500 nm, and slit width of 100 nm. Each slit of the nanocomb was most likely formed by a directed morphology change of a row of 200 nm pores to a single open slit following Ge incorporation into the developing frustule during the final cell division. The frustules possessed blue photoluminescence at peak wavelengths between 450 and 480 nm, which was attributed to contributions from nanostructured biosilica in both the parent valves and in the nanocomb daughter valves. This is the first reported study of using a cell culture system to biologically fabricate a photoluminescent nanocomb structure.
硅藻是单细胞藻类，能制造具有复杂纳米级特征（如二维孔阵列）的微米级二氧化硅外壳或“壳套”。在本研究中，通过两阶段培养过程将低水平的锗代谢插入到羽纹硅藻菱形藻的壳套生物二氧化硅中，诱导形成了与双面纳米梳结构极为相似的壳套。两阶段培养过程的最终产物在生物二氧化硅中含有0.41 wt%的锗，由具有正常二维200 nm孔阵列的母壳瓣和具有纳米梳结构的子壳瓣的等量混合物组成。纳米梳结构的总长度为8μm，肋宽为200 nm，肋长为500 nm，狭缝宽度为100 nm。纳米梳的每个狭缝很可能是在最终细胞分裂过程中锗掺入正在发育的壳套后，一排200 nm的孔定向形态变化为单个开放狭缝而形成的。壳套在450至480 nm的峰值波长处具有蓝色光致发光，这归因于母壳瓣和纳米梳子壳瓣中纳米结构生物二氧化硅的贡献。这是首次报道使用细胞培养系统生物制造光致发光纳米梳结构的研究。
