A prototype instrument has been constructed to measure individual airborne particles based on their aerodynamic size and their intrinsic fluorescence at selected excitation and emission wavelength bands. The instrument combines features of an aerodynamic particle sizing device with capabilities similar to those of a liquid flow cytometer. The goal of the instrument is to provide real-time data indicative of particle characteristics, and it is especially targeted to respond to bioaerosols from 0.5 to 10 micrometers (aerodynamic diameter) with intrinsic fluorescence exited at a wavelength of 325 nm and emitting from 420 to 580 nm. This size range covers individual airborne bacteria and bacteria clusters, and the fluorescence sensitivity is selected for biological molecules commonly found in cellular systems, for example, reduced nicotinamide adenine dinucleotide phosphate [NAD(P)H] and riboflavin. Initial tests with nebulised Bacillus subtilis var. niger (BG, ATCC 9372) spores have shown that, for both individual spores and spore clumps, a low level of fluorescence is detected from 17% of the particles. This detection percentage is on the same order as previous experiments that have measured viability of about 12% for mechanically dispersed BG spores (Ho and Fisher (1993) Defense Research Establishment Suffield Memorandum 1421) and suggests a need for further investigation into the possible relationship between the detected fluorescence and viability of bacterial spores.

中文翻译：

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通过同时测量粒子空气动力学尺寸和固有荧光实时检测生物气溶胶的仪器设计

已经构建了一个原型仪器，用于根据空气动力学尺寸及其在选定激发和发射波长带下的固有荧光来测量单个空气传播粒子。该仪器结合了空气动力学粒度装置的特点和类似于液体流式细胞仪的功能。该仪器的目标是提供指示颗粒特性的实时数据，特别是针对 0.5 到 10 微米（空气动力学直径）的生物气溶胶的响应，其固有荧光在 325 nm 的波长处发出并从 420 到580 纳米。该尺寸范围涵盖了单个空气传播细菌和细菌簇，并且针对细胞系统中常见的生物分子选择了荧光灵敏度，例如，还原烟酰胺腺嘌呤二核苷酸磷酸 [NAD(P)H] 和核黄素。雾化枯草芽孢杆菌变种的初步测试。niger (BG, ATCC 9372) 孢子表明，对于单个孢子和孢子团，从 17% 的颗粒中检测到低水平的荧光。该检测百分比与之前的实验相同，这些实验测量了机械分散的 BG 孢子的存活率约为 12%（Ho 和 Fisher（1993）国防研究机构萨菲尔德备忘录 1421），并表明需要进一步调查之间可能的关系检测到的细菌孢子的荧光和活力。从 17% 的颗粒中检测到低水平的荧光。该检测百分比与之前的实验相同，这些实验测量了机械分散的 BG 孢子的存活率约为 12%（Ho 和 Fisher（1993）国防研究机构萨菲尔德备忘录 1421），并表明需要进一步调查之间可能的关系检测到的细菌孢子的荧光和活力。从 17% 的颗粒中检测到低水平的荧光。该检测百分比与之前的实验相同，这些实验测量了机械分散的 BG 孢子的存活率约为 12%（Ho 和 Fisher（1993）国防研究机构萨菲尔德备忘录 1421），并表明需要进一步调查之间可能的关系检测到的细菌孢子的荧光和活力。