In this work, a chemical sensor based on an In-fiber optic Mach-Zehnder Interferometer (MZI) is reported. The MZI is fabricated using standard single-mode fiber with a waist-enlarged splicing method, where the spliced point acts as a coupling and re-coupling element for cladding modes and core mode. Unlike conventional transmission based MZIs, a reflective configuration is prepared by coating the fiber tip with silver developing a convenient fiber optic probe. A sensitivity of about 125 nm/RIU to the surrounding medium refractive index is obtained. As an application, the biofilm growth of a Gram-negative aerobic bacterium, i.e. Pseudomonas alcaligenes, is observed by monitoring the resonance wavelength shifts in real-time over three days. Biofilm thickness is further analyzed by using Atomic Force Microscopy technique demonstrating the effectiveness of fiber optic technology for real time continuous monitoring of biofilm growth.
Fiber optic sensors based on Mach-Zehnder Interferometer for the detection of bacterial biofilms
Rashidi, A.;Esposito, F.;Srivastava, A.;Campopiano, S.;Iadicicco, A.
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2025-01-01
Abstract
In this work, a chemical sensor based on an In-fiber optic Mach-Zehnder Interferometer (MZI) is reported. The MZI is fabricated using standard single-mode fiber with a waist-enlarged splicing method, where the spliced point acts as a coupling and re-coupling element for cladding modes and core mode. Unlike conventional transmission based MZIs, a reflective configuration is prepared by coating the fiber tip with silver developing a convenient fiber optic probe. A sensitivity of about 125 nm/RIU to the surrounding medium refractive index is obtained. As an application, the biofilm growth of a Gram-negative aerobic bacterium, i.e. Pseudomonas alcaligenes, is observed by monitoring the resonance wavelength shifts in real-time over three days. Biofilm thickness is further analyzed by using Atomic Force Microscopy technique demonstrating the effectiveness of fiber optic technology for real time continuous monitoring of biofilm growth.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
