Infectious diseases are worldwide a major cause of morbidity and mortality. Fast and specific detection of pathogens such as bacteria is needed to combat these diseases. Optimal methods would be non-invasive and without extensive sample-taking/processing. Here, we developed a set of near infrared (NIR) fluorescent nanosensors and used them for remote fingerprinting of clinically important bacteria. The nanosensors are based on single-walled carbon nanotubes (SWCNTs) that fluoresce in the NIR optical tissue transparency window, which offers ultra-low background and high tissue penetration. They are chemically tailored to detect released metabolites as well as specific virulence factors (lipopolysaccharides, siderophores, DNases, proteases) and integrated into functional hydrogel arrays with 9 different sensors. These hydrogels are exposed to clinical isolates of 6 important bacteria (Staphylococcus aureus, Escherichia coli,…) and remote (≥25 cm) NIR imaging allows to identify and distinguish bacteria. Sensors are also spectrally encoded (900 nm, 1000 nm, 1250 nm) to differentiate the two major pathogens P. aeruginosa as well as S. aureus and penetrate tissue (>5 mm). This type of multiplexing with NIR fluorescent nanosensors enables remote detection and differentiation of important pathogens and the potential for smart surfaces.

传染病是全世界发病率和死亡率的主要原因。为了与这些疾病作斗争，需要对细菌等病原体进行快速，特异性的检测。最佳方法将是非侵入性的，并且无需大量的样本采集/处理。在这里，我们开发了一套近红外（NIR）荧光纳米传感器，并将其用于临床上重要细菌的远程指纹识别。纳米传感器基于单壁碳纳米管（SWCNT），该碳纳米管在NIR光学组织透明窗口中发出荧光，从而提供超低的背景和较高的组织穿透力。它们经过化学修饰，可检测释放的代谢物以及特定的毒力因子（脂多糖，铁载体，DNases，蛋白酶），并通过9种不同的传感器整合到功能性水凝胶阵列中。金黄色葡萄球菌，大肠杆菌等）和远距离（≥25cm）NIR成像可以识别和区分细菌。传感器还进行了光谱编码（900 nm，1000 nm，1250 nm），以区分两种主要病原体铜绿假单胞菌和金黄色葡萄球菌并穿透组织（> 5 mm）。这种与NIR荧光纳米传感器的多路复用可实现对重要病原体的远程检测和区分以及智能表面的潜力。