A GaAs 2D photonic crystal biosensor for waterborne detection

Monitoring waterborne and foodborne bacteria in drinking water and food is becoming a primary issue due to these bacteria having the potential to cause illness and harm human health. In this article, we design a new two-dimension (2D) photonic crystal biosensors for detecting waterborne bacteria, such as Vibrio cholerae, Escherichia coli (E. coli), Shigella flexneri and Salmonella. Our sensor is composed of air holes in a Gallium arsenide photonic crystal slab, using the plane wave expansion (PWE) and the finite difference time domain (FDTD) methods to develop and analysis the biosensor. The proposed biosensor has a high Q-factor of 9227.9, a sensitivity of 226.97, a high figure of merit (FOM) of 2269.7 RIU⁻¹, a detection limit of 4.405 · 10^-4 RIU, a smallest size of 23.28 µm² for detection. The device can augment the capabilities of biological devices for waterborne and foodborne bacteria detection.