Development of an Immunocapture-Based Polymeric Optical Fiber Sensor for Bacterial Detection in Water

Abstract

Conventional methods for pathogen detection in water rely on time-consuming enrichment steps followed by biochemical identification strategies, which require assay times ranging from 24 hours to a week. However, in recent years, significant efforts have been made to develop biosensing technologies enabling rapid and close-to-real-time detection of waterborne pathogens. In previous studies, we developed a plastic optical fiber (POF) immunosensor using an optoelectronic configuration consisting of a U-Shape probe connected to an LED and a photodetector. Bacterial detection was evaluated with the immunosensor immersed in a bacterial suspension in water with a known concentration. Here, we report on the sensitivity of a new optoelectronic configuration consisting of two POF U-shaped probes, one as the reference and the other as the immunosensor, for the detection of Escherichia coli. In addition, another methos of detection was tested where the sensors were calibrated in the air, before being immersed in a bacterial suspension and then read in the air. This modification improved sensor sensitivity and resulted in a faster detection time. After the immunocapture, the sensors were DAPI-stained and submitted to confocal microscopy. The histograms obtained confirmed that the responses of the immunosensors were due to the bacteria. This new sensor detected the presence of E. coli at 104 CFU/mL in less than 20 min. Currently, sub-20 min is faster than previous studies using fiber-optic based biosensors. We report on an inexpensive and faster detection technology when compared with conventional methods.

A Review of Wearable Optical Fiber Sensors for Rehabilitation Monitoring

“…Recent advancements in optical fiber sensing technology have established optical fiber sensors as viable alternatives to electronic sensors in wearable rehabilitation devices, emphasizing their key benefit: inherent immunity to electromagnetic interference. Furthermore, optical fiber sensors have found broad applications across the medical field [ 15 , 16 , 17 ], and optical fiber sensors are also utilized in sectors such as oil and gas [ 18 ], structural monitoring [ 19 ], environmental monitoring [ 20 ], aerospace [ 21 , 22 ], and industrial automation [ 23 ], benefited by their lightweight, compact size, high sensitivity, capability for remote measurement, ability to conduct multi-parameter measurements, and the capacity to integrate into sensor networks alongside other types of sensors.…”