Department of Chemical Engineering, University of Waterloo, 200 University Avenue W, Waterloo, Ontario, Canada N2L 3G1; Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue W, Waterloo, Ontario, Canada N2L 3G1.
Department of Chemical Engineering, University of Waterloo, 200 University Avenue W, Waterloo, Ontario, Canada N2L 3G1.
Biosens Bioelectron. 2014 Nov 15;61:386-90. doi: 10.1016/j.bios.2014.05.045. Epub 2014 May 27.
Ocular pathogens can cause serious damages in the eye leading to severe vision loss and even blindness if left untreated. Identification of pathogens is crucial for administering the appropriate antibiotics in order to gain effective control over ocular infection. Herein, we report a gold nanostar based "chemical nose" for visually identifying ocular pathogens. Using a spectrophotometer and nanostars of different sizes and degrees of branching, we show that the "chemical nose" is capable of identifying the following clinically relevant ocular pathogens with an accuracy of 99%: S. aureus, A. xylosoxidans, D. acidovorans and S. maltophilia. The differential colorimetric response is due to electrostatic aggregation of cationic gold nanostars around bacteria without the use of biomolecule ligands such as aptamers or antibodies. Transmission electron microscopy confirms that the number of gold nanostars aggregated around each bacterium correlates closely with the colorimetric response. Thus, gold nanostars serve as a promising platform for rapid visual identification of ocular pathogens with application in point-of-care diagnostics.
眼表病原体如果得不到及时治疗，可能会导致严重的眼部损伤，甚至失明。为了对眼部感染进行有效控制，明确病原体至关重要。本研究报告了一种基于金纳米星的“化学鼻”，用于直观地识别眼表病原体。通过分光光度计和不同尺寸及分支程度的纳米星，我们证明了“化学鼻”能够以 99%的准确率识别以下具有临床相关性的眼表病原体：金黄色葡萄球菌、木糖氧化无色杆菌、嗜酸寡养单胞菌和嗜麦芽寡养单胞菌。这种差分比色响应归因于阳离子金纳米星在没有使用适体或抗体等生物分子配体的情况下，围绕细菌发生静电聚集。透射电子显微镜证实，聚集在每个细菌周围的金纳米星数量与比色响应密切相关。因此，金纳米星为快速直观地识别眼表病原体提供了一个很有前途的平台，有望应用于即时诊断。
