BioNanotechnology and Microbiology Laboratory, Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Universidad Andres Bello, Av. República 239, 8370146, Santiago, PC, Chile.
Biochemistry and Microbial Genomics Department, Instituto de Investigaciones Biológicas Clemente Estable, Av. Italia 3318, 11600, Montevideo, PC, Uruguay.
Microb Cell Fact. 2021 Feb 10;20(1):41. doi: 10.1186/s12934-021-01531-4.
Microbes are present in almost every environment on Earth, even in those with extreme environmental conditions such as Antarctica, where rocks may represent the main refuge for life. Lithobiontic communities are composed of microorganisms capable of colonizing rocks and, as it is a not so well studied bacterial community, they may represent a very interesting source of diversity and functional traits with potential for biotechnological applications. In this work we analyzed the ability of Antarctic lithobiontic bacterium to synthesize cadmium sulfide quantum dots (CdS QDs) and their potential application in solar cells.
A basaltic andesite rock sample was collected from Fildes Peninsula, King George Island, Antarctica, and processed in order to isolate lithobiontic bacterial strains. Out of the 11 selected isolates, strain UYP1, identified as Pedobacter, was chosen for further characterization and analysis due to its high cadmium tolerance. A protocol for the biosynthesis of CdS QDs was developed and optimized for this strain. After 20 and 80 min of synthesis, yellow-green and orange-red fluorescent emissions were observed under UV light, respectively. QDs were characterized through spectroscopic techniques, dynamic light scattering analysis, high-resolution transmission electron microscopy and energy dispersive x-ray spectroscopy. Nanostructures of 3.07 nm, composed of 51.1% cadmium and 48.9% sulfide were obtained and further used as photosensitizer material in solar cells. These solar cells were able to conduct electrons and displayed an open circuit voltage of 162 mV, a short circuit current density of 0.0110 mA cm, and had an efficiency of conversion up to 0.0016%, which is comparable with data previously reported for solar cells sensitized with biologically produced quantum dots.
We report a cheap, rapid and eco-friendly protocol for the production of CdS QDs by an Antarctic lithobiontic bacterium, Pedobacter, a genus that was not previously reported as a quantum dot producer. The application of the biosynthesized QDs as sensitizer material in solar cells was validated.
微生物存在于地球上几乎每一个环境中，即使是在南极洲等极端环境条件下，岩石可能是生命的主要避难所。生石生物群落由能够定殖于岩石的微生物组成，由于这是一个尚未得到充分研究的细菌群落，它们可能代表着具有潜在生物技术应用的多样性和功能特性的非常有趣的来源。在这项工作中，我们分析了南极生石细菌合成硫化镉量子点（CdS QDs）的能力及其在太阳能电池中的潜在应用。
从南极洲乔治王岛菲尔德斯半岛采集了一块玄武安山岩样本，并对其进行处理，以分离生石细菌菌株。在 11 株选定的分离株中，由于其高镉耐受性，Pedobacter 属的 UYP1 菌株被选为进一步表征和分析的菌株。为该菌株开发并优化了 CdS QDs 的生物合成方案。在合成 20 和 80 分钟后，分别在紫外光下观察到黄绿色和橙红色荧光发射。通过光谱技术、动态光散射分析、高分辨率透射电子显微镜和能量色散 X 射线光谱对 QDs 进行了表征。获得了由 51.1%镉和 48.9%硫化物组成的 3.07nm 纳米结构，并进一步将其用作太阳能电池中的光敏材料。这些太阳能电池能够传导电子，并显示出 162mV 的开路电压、0.0110mA·cm 的短路电流密度和高达 0.0016%的转换效率，这与以前报道的用生物合成量子点敏化的太阳能电池的数据相当。
我们报告了一种由南极生石细菌 Pedobacter 生产 CdS QDs 的廉价、快速和环保的方案，该属以前未被报道为量子点的生产者。验证了生物合成的 QDs 作为敏化材料在太阳能电池中的应用。
