Key Laboratory of Green Printing, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing, 100190, P. R. China.
School of Physics, ITMO University, Saint Petersburg, 197101, Russia.
Adv Mater. 2023 Mar;35(12):e2211363. doi: 10.1002/adma.202211363. Epub 2023 Feb 17.
Fast and accurate detection of microbial cells in clinical samples is highly valuable but remains a challenge. Here, a simple, culture-free diagnostic system is developed for direct detection of pathogenic bacteria in water, urine, and serum samples using an optical colorimetric biosensor. It consists of printed nanoarrays chemically conjugated with specific antibodies that exhibits distinct color changes after capturing target pathogens. By utilizing the internal capillarity inside an evaporating droplet, target preconcentration is achieved within a few minutes to enable rapid identification and more efficient detection of bacterial pathogens. More importantly, the scattering signals of bacteria are significantly amplified by the nanoarrays due to strong near-field localization, which supports a visualizable analysis of the growth, reproduction, and cell activity of bacteria at the single-cell level. Finally, in addition to high selectivity, this nanoarray-based biosensor is also capable of accurate quantification and continuous monitoring of bacterial load on food over a broad linear range, with a detection limit of 10 CFU mL . This work provides an accessible and user-friendly tool for point-of-care testing of pathogens in many clinical and environmental applications, and possibly enables a breakthrough in early prevention and treatment.
快速准确地检测临床样本中的微生物细胞具有重要价值，但仍然是一个挑战。在这里，开发了一种简单的、无需培养的诊断系统，用于使用光学比色生物传感器直接检测水、尿液和血清样本中的致病菌。它由印刷的纳米阵列组成，这些纳米阵列通过化学方法与特定抗体结合，在捕获目标病原体后会发生明显的颜色变化。通过利用蒸发液滴内部的毛细作用，在几分钟内实现目标物的预浓缩，从而能够快速识别和更有效地检测细菌病原体。更重要的是，由于强近场定位，纳米阵列显著放大了细菌的散射信号，支持在单细胞水平上可视化分析细菌的生长、繁殖和细胞活性。最后，除了高选择性之外，这种基于纳米阵列的生物传感器还能够在很宽的线性范围内对食品中的细菌负荷进行准确的定量和连续监测，检测限为 10 CFU mL-1。这项工作为许多临床和环境应用中的病原体即时检测提供了一种易于使用的工具，并可能为早期预防和治疗提供突破。
