Pertussis (or whooping cough) is a contagious disease mainly affecting infants and children and predominantly caused by Bordetella pertussis followed by Bordetella parapertussis. B. parapertussis causes a milder cough but usually symptomatically appears like B. pertussis infection. Thus the epidemiology of illness caused by B. parapertussis is not well understood. In this study, a sensitive and specific method for the rapid diagnosis of B. parapertussis is presented. The covalent immobilization of thiol-terminated DNA oligonucleotides (ss DNA SAM) on a silicon surface by disulfide bond formation is investigated with atomic force microscopy (AFM) and ellipsometry. The measurements indicated an average layer thickness of 5 ± 0.84 nm for 2 μg/μl concentration and 24 h incubation time. This thickness changed to 8.4 ± 0.92 nm for the same concentration (2 μg/μl) by altering the incubation time to 48 h. Ellipsometric data recorded before and after hybridization of B. parapertussis revealed an increase in mean grain area from 91 nm2 to 227 nm2 and a change in the refractive index from 1.489 to 1.648 for 2 μg/μl B. parapertussis, respectively. This change in the refractive index was used to evaluate the amount of adsorbed molecules and their density. The results showed that the density of adsorbed molecules increased from 0.2 to 0.97 g/cm3 after B. parapertussis attachment, respectively. To confirm the hybridization of B. parapertussis to ss DNA SAM, the ds DNA SAM was denatured and the ss DNA SAM surface was reproduced with an average height variation of 6.42 ± 0.75 nm. This showed the stability of the DNA film that can be tuned by varying the concentration and incubation time, thus providing a robust method for the label-free detection of B. parapertussis other than routinely used PCR detection.

中文翻译：

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基于椭圆光度法的新型 DNA 生物传感器，用于无标记、实时检测副百日咳博德特氏菌

百日咳（或百日咳）是一种主要影响婴儿和儿童的传染病，主要由百日咳博德特氏菌引起，其次是副百日咳博德特氏菌。副百日咳博德特氏菌引起较轻微的咳嗽，但通常症状类似于百日咳博德特氏菌感染。因此，副百日咳博德特氏菌引起的疾病的流行病学尚不清楚。本研究提出了一种灵敏且特异的副百日咳博德特氏菌快速诊断方法。使用原子力显微镜 (AFM) 和椭圆光度法研究了通过形成二硫键将硫醇封端的 DNA 寡核苷酸 (ss DNA SAM) 共价固定在硅表面上。测量结果表明，在 2 μg/μl 浓度和 24 小时孵育时间下，平均层厚度为 5 ± 0.84 nm。通过将孵育时间更改为 48 小时，对于相同浓度 (2 μg/μl)，该厚度变为 8.4 ± 0.92 nm。副百日咳杆菌杂交前后记录的椭圆光度数据显示，2 μg/μl 副百日咳杆菌的平均颗粒面积分别从 91 nm2 增加到 227 nm2，折射率从 1.489 变化到 1.648。折射率的变化用于评估吸附分子的数量及其密度。结果表明，副百日咳杆菌附着后，吸附分子的密度分别从0.2 g/cm3增加到0.97 g/cm3。为了确认副百日咳博德特氏菌与单链 DNA SAM 的杂交，双链 DNA SAM 被变性，并以 6.42 ± 0.75 nm 的平均高度变化复制单链 DNA SAM 表面。这表明DNA膜的稳定性可以通过改变浓度和孵育时间来调节，从而为副百日咳杆菌的无标记检测提供了除常规PCR检测之外的稳健方法。