Bacterial Detection for Food Inspection by Using a Metallic Mesh Sensor

We demonstrated easy and rapid detections of E. coli without culturing and labeling by using a metallic mesh sensor. E. coli in saline was filtrated by a membrane filter, and attached to the surface of the metallic mesh. Transmission spectra of these samples were measured around 1 THz, where the membrane filter has low absorption. With increasing concentration of E. coli, spectral shifts also increased, and a distinct shift was observed at 106 mL–1 (3.5 μg, 26 ng/mm2), whereas there was no distinct change in transmission without the metallic mesh. Finally, no interference of proteins with the detection was confirmed.