Department of Nanoscience and Technology, Bharathiar University, Coimbatore, Tamilnadu, 641046, India.
Environ Sci Pollut Res Int. 2018 Jul;25(21):20540-20549. doi: 10.1007/s11356-017-0916-z. Epub 2017 Dec 14.
In the present study, an attempt was made to develop a proof of concept for the detection of nitroaromatic explosive derivatives through the photoluminescence (PL) quenching process using functionalized diatom frustules as a sensing platform. The diatom frustules are composed of nanostructured, highly porous biogenic silica material and emit strong, visible blue PL upon UV excitation. PL-active biosilica was isolated from the marine diatom Nitzschia sp. and was amine-functionalized to develop a sensing platform. Functionalized diatom frustules were further characterized using field emission scanning electron microscope and a series of spectroscopic methods. When nitroaromatic compounds were bound to the functionalized diatom frustules biosilica, the PL intensity from the functionalized biosilica was partially quenched due to the electrophilic nature of the nitro (-NO) groups. The quenching process confirmed the Meisenheimer complex formation and was investigated by using Fourier transform infrared spectroscopy and time-resolved photoluminescence studies. The developed platform was further evaluated for its sensitivity and specificity, and the limit of detection (LOD) of the assay was determined as 1 μM for a series of nitroaromatic explosive compounds. In conclusion, the developed sensing platform will have great utility in the development of on-site detection platforms for sensitive detection of warfare explosive nitroaromatic compounds from the environment.
在本研究中，我们尝试通过光致发光（PL）猝灭过程，利用功能化的硅藻壳作为传感平台，来检测硝基芳香族爆炸物衍生物。硅藻壳由纳米结构的、高度多孔的生物成因硅材料组成，在紫外光激发下会发出强烈的可见蓝光 PL。从海洋硅藻 Nitzschia sp. 中分离出具有 PL 活性的生物硅，并对其进行胺功能化，以开发传感平台。进一步使用场发射扫描电子显微镜和一系列光谱方法对功能化硅藻壳进行了表征。当硝基芳香族化合物与功能化硅藻壳生物硅结合时，由于硝基（-NO）基团的亲电性，功能化生物硅的 PL 强度部分猝灭。猝灭过程证实了 Meisenheimer 配合物的形成，并通过傅里叶变换红外光谱和时间分辨光致发光研究进行了研究。进一步评估了所开发的平台的灵敏度和特异性，并确定该测定法的检测限（LOD）为 1 μM，可用于一系列硝基芳香族爆炸物化合物。总之，所开发的传感平台将在开发用于从环境中灵敏检测战争用爆炸物硝基芳香族化合物的现场检测平台方面具有重要的应用价值。
