Rapid detection of pathogenic bacteria is one of the important social issues for preventing and identifying cause of problems affecting human health. Ionic current sensing through pores has shown the ability to electrically measure bacteria. However, there is an inherent limitation to discriminate chemical characteristics of bacteria for existing ionic current sensing methods Here we propose a real-time simultaneous measurement method, which combines ionic current sensing and fluorescence observation on a microfluidic device. Our method can detect not only the size of individual bacteria passing through a micropore but also observe their stainability based on chemical properties of bacterial cell surface within 300 ms. We succeeded in discriminating each bacterium in a solution mixture including contaminant particles by combining highly accurate ionic current sensing which can detect a size difference of 70 nm, and fluorescence observation which can discriminate internal structures such as those that define bacteria as gram-positive or gram-negative. Our method can be applied to not only on-site bacteria detection but also to screening technology.

快速检测病原细菌是预防和识别影响人类健康的问题原因的重要社会问题之一。通过孔的离子电流感测已经显示出能够电测量细菌的能力。然而，对于现有的离子电流感测方法来说，区分细菌的化学特性存在固有的局限性。在此，我们提出了一种实时同时测量方法，该方法将离子电流感测和在微流体装置上的荧光观察相结合。我们的方法不仅可以检测穿过微孔的单个细菌的大小，还可以基于300 ms内细菌细胞表面的化学特性观察其可染色性。我们通过结合可以检测70 nm大小差异的高精度离子电流检测和可以区分内部结构（例如将细菌定义为革兰氏阳性或革兰氏菌的内部结构）的荧光观察相结合，成功地辨别了包含污染物颗粒的溶液混合物中的每种细菌-消极的。我们的方法不仅可以应用于现场细菌检测，而且可以应用于筛选技术。