Optical Fibers As Chemical Optical Interfaces For Bio-sensing And Controlled Release Applications

This thesis work, covers sensing and controlled release applications based on optical fibers,because in the photonics industry optical fibers are an established and proven technology.Recently optical fibers have made in-roads into medicine, intelligent textiles etc. The mainreasons for choosing optical fibers over nano-fibers are as follows, nanofibers and health risk-inhaling tiny fibers made by the nanotechnology industry could cause similar health problemsto asbestos. Some are similar in shape to asbestos fibers, which have caused lung cancers suchas mesothelioma.Mathematical models for the optical-fiber based bio-sensors and controlled releasesystems were established, the models developed are permitted to build new trigger bio-sensors (in particular, by utilizing the scheme we considered) based on Faraday’s and Fick’sLaws and the simulation was successful. A highly sensitive Optical Fiber bio-sensor wasdeveloped and signal amplification met the expectation (85%). High performance computingsoftware and super computer were used to perform the simulations. The results of thecomputational modeling indicated that bio-sensor response is highly stable at the relativelythick external diffusion layer.We modeled the in-vitro based analysis of the Optical Fiber based Controlled ReleaseSystem, as a three dimensional Reaction-Diffusion problem with mass transfer boundaryconditions. We assumed first order kinetics for the enzymatic degradation of the bio-molecules on the surface modified Optical Fibers. Mathematical modeling, along withnumerical simulation, can provide useful guidance and insight to the experimentalist incontrolled release, and can greatly reduce the number of experiments needed in order toobtain the desired release profile.Our Bio-Sensor Fabrication is a highly novel concept based on an important protocol. It isobserved from the literature that the fabrication process involves20-35steps whereas ourresearch program derived a much shorter15-20step approach leading to an internationalpatent. Characterization of the chemical optical surfaces was investigated usingchemiluminescence and Scanning Electron Microscopy to complete the optical-fiber basedbio-sensor fabrication and analysis. The results presented in this study demonstrate that a rapid, specific, sensitive and semi-quantitative anti-GIPC-1IgM optical fiber immunoassay, that can be created by covalentmodification of the core of an optical fiber tip with GIPC-1protein and its signal responsewas successfully captured by the biosensor Chemiluminescence/photomultiplier tube(CL/PMT) Test Bed System. A graph was plotted by using RLU vs GIPC-1concentrationsand the sensor signal was observed.A general purpose Nano-Bio optical fiber based control release platform, was constructedand demonstrated to further the advancement, of microfluidics and controlled release of Bio-molecules, using High intensity focused ultrasound system, HIFU VCX400Liquid Processor.This novel utility nano-bio platform, was achieved by the chemical modification of theOptical Fibers, then dip coating, the silanized Optical Fibers with Glycine microspheres, tocovalently bind the Glycine microspheres, onto the silanized optical fibers. We finallydemonstrated the controlled release, of the Glycine microspheres, from the silanized opticalfibers, using ultrasonic irradiation, from the VCX400ultrasonic liquid processor, based oncertain control parameters like amplitude and time. The analysis was done using ScanningElectron Microscopy and Raman Spectroscopy. The Glycine microspheres that were coatedonto the silanized optical fiber were successfully released into the ddW test tube/Glass wareand the pH value of the distilled water was tested with a litmus paper, the pH value ofdistilled water changed to5.5. Further we also measured and observed the Raman Shift ofGlycine in distilled water under different concentrations. It could be concluded that thecontrolled release of Glycine microspheres into water was successful. Two graphs wereplotted with Raman Shift and its laser intensity.Chemical optical interfaces are an interesting source to develop novel sensors andcontrolled release systems. Intelligent and smart textiles for medicine and space applicationsbased on optical fibers will have great potential in various applications.