Singh, M.Raghuwanshi, S.K.2026-02-052020Review of Scientific Instruments, 2020, 91, 12, pp. -346748https://doi.org/10.1063/5.0020571https://idr.nitk.ac.in/handle/123456789/23551In this work, a TiO2 coated etched long-period grating (e-LPG) fiber optic biosensor is developed for the detection of Escherichia coli (E. coli) bacteria in food items. Label-free Escherichia coli bacteria monitoring is done over the detection range of 0 cfu/ml-50 cfu/ml using an advanced spectral interrogation mechanism. The thin film deposition of 40 nm TiO2 over the e-LPG is confirmed by the microscopy method, such as scanning electron microscopy. In our proposed biosensor design, T4-bacteriophage is covalently immobilized over the TiO2 coated fiber surface. This biosensor system has reached sensitivity at 2.55 nm/RIU. Our experiments confirm the resolution and the limit of detection (3?/S) of 0.0039 RIU and 10.05 ppm, respectively. The proposed biosensor with enhanced sensitivity is suitable for monitoring harmful pathogens/infectious agents in various food products. © 2020 Author(s).DepositionEscherichia coliFiber optic sensorsFiber opticsFood productsOxide mineralsScanning electron microscopyTitanium dioxideBio-sensor systemsEnhanced sensitivityEscherichia coli (E. coli)Escherichia coli bacteriaFiber optic biosensorLimit of detectionLong Period GratingsThin-film depositionsBiosensorsoptic nerve fibertitaniumtitanium dioxidedevicesfood controlgenetic proceduresisolation and purificationlimit of detectionrefractometryBiosensing TechniquesFood MicrobiologyLimit of DetectionOptical FibersRefractometryTitanium