University of North Carolina, Charlotte, NC, USA.
Methods Mol Biol. 2023;2709:299-307. doi: 10.1007/978-1-0716-3417-2_21.
DNA-templated silver nanoclusters (DNA-AgNCs) are a unique class of bioinorganic nanomaterials. The optical properties and biological activities of DNA-AgNCs are readily modulated by the minor adjustments in the sequence or structure of the templating oligonucleotide. Excitation-emission matrix spectroscopy (EEMS) enables the fluorescence of compounds to be measured in a way that examines the entirety of a material's fluorescent properties. The use of EEMS for the characterization of DNA-AgNCs allows for multiple fluorescence peaks to be readily identified while providing the excitation and emission wavelengths of each signal. To assess the antibacterial and cytotoxic activities of DNA-AgNCs, two separate experimental approaches are used. Assessing the growth of bacteria over time is accomplished by measuring the optical density of the bacterial suspension with 600 nm light, which is directly related to the number of bacteria in suspension. In order to evaluate the DNA-AgNCs for cytotoxic activity, cell viability assays which probe mitochondrial activity were used. Herein, we describe protocols for the characterization of the fluorescent, antibacterial, and cytotoxic activities of DNA-AgNCs using EEM, optical density measurements, and cell viability assays.
DNA 模板银纳米团簇（DNA-AgNCs）是一类独特的生物无机纳米材料。DNA-AgNCs 的光学性质和生物活性可以通过模板寡核苷酸序列或结构的微小调整来轻松调节。激发-发射矩阵光谱（EEMS）可用于以检查材料荧光性质的整体的方式测量化合物的荧光。使用 EEMS 对 DNA-AgNCs 的特性进行分析，可以轻松识别多个荧光峰，并提供每个信号的激发和发射波长。为了评估 DNA-AgNCs 的抗菌和细胞毒性活性，使用了两种独立的实验方法。通过用 600nm 光测量细菌悬浮液的光密度来评估随时间推移细菌的生长情况，该光密度与悬浮液中的细菌数量直接相关。为了评估 DNA-AgNCs 的细胞毒性活性，使用了探测线粒体活性的细胞活力测定法。在此，我们描述了使用 EEM、光密度测量和细胞活力测定法来表征 DNA-AgNCs 的荧光、抗菌和细胞毒性活性的方案。
