De Angelis Roberta, Melino Sonia, Prosposito Paolo, Casalboni Mauro, Lamastra Francesca Romana, Nanni Francesca, Bruno Laura, Congestri Roberta
University of Rome 'Tor Vergata', Department of Industrial Engineering, Rome, Italy.
INSTM Consortium, Research Unit Roma Tor Vergata, Rome, Italy.
PLoS One. 2016 Nov 9;11(11):e0165571. doi: 10.1371/journal.pone.0165571. eCollection 2016.
A native isolate of the colonial benthic diatom Staurosirella pinnata was cultivated for biosilica production. The silicified cell walls (frustules) were used as a source of homogeneous and structurally predictable porous biosilica for dye trapping and random laser applications. This was coupled with the extraction of lipids from biomass showing potential to fabricate photoactive composite materials sustainably. The strain was selected for its ease of growth in culture and harvesting. Biosilica and lipids were obtained at the end of growth in indoor photobioreactors. Frustules were structurally characterized microscopically and their chemistry analyzed with Fourier Transform Infrared Spectroscopy. Frustule capacity of binding laser dyes was evaluated on a set of frustules/Rhodamine B (Rho B) solutions and with respect to silicon dioxide and diatomite by Fluorescence Spectroscopy demonstrating a high affinity for the organic dye. The effect of dye trapping property in conveying Rho B emission to frustules, with enhancement of scattering events, was analyzed on Rho B doped polyacrylamide gels filled or not with frustules. Amplified spontaneous emission was recorded at increasing pump power indicating the onset of a random laser effect in frustule filled gels at lower power threshold compared to unfilled matrices.
培养了一种底栖殖民硅藻——羽纹拟星杆藻的本地分离株用于生物二氧化硅生产。硅化细胞壁（壳片）被用作均匀且结构可预测的多孔生物二氧化硅来源，用于染料捕获和随机激光应用。这与从生物质中提取脂质相结合，显示出可持续制造光活性复合材料的潜力。选择该菌株是因其易于在培养和收获中生长。在室内光生物反应器中生长结束时获得了生物二氧化硅和脂质。通过显微镜对壳片进行结构表征，并使用傅里叶变换红外光谱分析其化学性质。通过荧光光谱法在一组壳片/罗丹明B（Rho B）溶液中以及相对于二氧化硅和硅藻土评估壳片结合激光染料的能力，结果表明其对有机染料具有高亲和力。在填充或未填充壳片的Rho B掺杂聚丙烯酰胺凝胶上分析了染料捕获特性在将Rho B发射传递到壳片并增强散射事件方面的效果。随着泵浦功率增加记录到放大自发发射，表明与未填充基质相比，填充壳片的凝胶在较低功率阈值下出现了随机激光效应。
