Development of nanobiosensors for diagnostics of bacterial pathogens

Abstract

Infectious diseases are posing to be a major healthcare problem newlinethroughout the world The contagious nature of these diseases makes it newlineimperative for early diagnosis of the microbial cause of infection to prevent newlinethe spread of epidemics Conventional standard diagnostic methods have newlinelimitations including laborious sample preparation poor sensitivity and newlinedelayed data readout Hence rapid field deployable diagnostic modalities are newlinein urgent need to combat the problems in identification of food contamination newlinedirect pathogen detection from clinical samples etc Nanobiotechnology based newlineapproach present a great opportunity to develop fast accurate and cost newlineeffective diagnostics The nanoparticles posses unique optical electrical and newlinemagnetic properties based on their core materials that renders them as a newlinesensitive signaling probes Also nanoparticles are amenable to surface newlinemodifications and biofunctionalization which can be exploited as target newlinespecific and sensitive signaling tool in the development of diagnostic newlinebiosensors newlineThis thesis aims to develop and compare various surface newlinechemistries biofunctionalization and detection strategies using nanoparticles newlinefor invitro diagnostics of infectious diseases suitable for developing newlinecountries To realize these objectives the magnetic nanoparticles gold newlinenanoparticles and dye doped silica nanoparticles were employed for nucleic newlineacid and antibody based detection of bacterial pathogens The magnetic newlinenanoparticles were covalently attached to antibody specific to the target newlinepathogen These immunomagnetic nanoparticles after incubation with newlinecontaminated food samples form a complex with the target pathogen A newlinesimple magnetic field can be applied to localize and collect the target newlinepathogen while the other contaminants can be easily washed away The newlineimmunomagnetic nanoparticles based approach thus speeds up sample newlinepreparation from low bacterial load samples to yield sufficient high purity newlineDNA required for PCR based detection newline newline newline newline newline newline newline newline newline newline newline newline newline newline