Applied Optics Complutense Group, Faculty of Optics and Optometry, University Complutense of Madrid, Av. Arcos de Jalón, 118, 28037, Madrid, Spain.
Centro de Investigación en Sanidad Animal, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Carretera Algete-El Casar de Talamanca, Km 8.1, 28130, Valdeolmos, Madrid, Spain.
Sci Rep. 2021 Jul 27;11(1):15293. doi: 10.1038/s41598-021-94648-w.
The optical absorption coefficient of culture media is critical for the survival analysis of pathogens under optical irradiation. The quality of the results obtained from experiments relies on the optical analysis of the spatial distribution of fluence which also depends on the geometry of the sample. In this contribution, we consider both the geometrical shape and the culture medium's absorption coefficient to evaluate how the spatial distribution of optical radiation affects pathogens/viruses. In this work, we exposed SARS-CoV-2 to UV-C radiation ([Formula: see text] = 254 nm) and we calculated-considering the influence of the optical absorption of the culture medium-a characteristic inactivation fluence of [Formula: see text] = 4.7 J/m, or an equivalent 10% survival (D90 dose) of 10.8 J/m. Experimentally, we diluted the virus into sessile drops of Dulbecco's Modified Eagle Medium to evaluate pathogen activity after controlled doses of UV irradiation. To validate the optical absorption mode, we carried out an additional experiment where we varied droplet size. Our model-including optical absorption and geometrical considerations-provides robust results among a variety of experimental situations, and represents our experimental conditions more accurately. These results will help to evaluate the capability of UV disinfecting strategies applied to a variety of everyday situations, including the case of micro-droplets generated by respiratory functions.
培养基的光吸收系数对于光照射下病原体的存活分析至关重要。实验结果的质量取决于对辐照度空间分布的光学分析，而这又取决于样品的几何形状。在本研究中，我们同时考虑了几何形状和培养基的吸收系数，以评估光辐射的空间分布如何影响病原体/病毒。在这项工作中，我们用 UV-C 辐射（[Formula: see text] = 254nm）照射 SARS-CoV-2，并考虑了培养基的光学吸收的影响，计算出特征灭活辐照量[Formula: see text] = 4.7 J/m，或等效的 10%存活（D90 剂量）为 10.8 J/m。在实验中，我们将病毒稀释到杜氏改良伊格尔培养基的静止液滴中，以评估经过受控剂量的 UV 照射后的病原体活性。为了验证光吸收模式，我们进行了额外的实验，其中改变了液滴的大小。我们的模型包括光吸收和几何考虑因素，在各种实验情况下提供了稳健的结果，并更准确地代表了我们的实验条件。这些结果将有助于评估紫外线消毒策略在各种日常情况下的应用能力，包括由呼吸功能产生的微液滴的情况。
