Sharif Digital Repository

The accurate assessment of biomarkers likes proteins, hormones or other biomolecules that amount of them changes with state of disease or level of treatment and gives diagnostic information is a difficult duty. In these samples, pathogens exist in small quantity compared to other background molecules. Therefore, appropriate sampling process for concentrating and separating pathogens from the matrix should be developed in order to provide rapid and accurate pathogen detection test. In this thesis design and fabrication of microfluidic biosensors based on the modified nanofibrous membranes were investigated and explained. PES nanofibrous membrane with carboxyl functional groups for covalent... 

The present study is aimed at the development of a novel approach based on the magnetically improvement of DNA-directed immobilization to prepare a highly efficient sensor for prostate diagnosis. The novelty of this work is in the use of antibody conjugated magnetic nanoparticles via DDI. DNA-modified magnetic nanoparticles are added in solution to capture DNA-conjugated, fluorescently-labeled immunocomplexes formed in solution free of steric constraints. The DDI-based nanoconstructs are then concentrated and immobilized using a magnetic field. Compared to a process in which the immunocomplex directly forms on the sensing surface, the proposed approach provides higher mass transfer and lower... 

In the first part of this research, we have developed a simple and effective ratiometric fluorescence sensor for selective detection of dopamine (DA) in alkaline media by simply mixing thioglycolic acid (TGA) functionalized orange fluorescent cadmium telluride (CdTe) quantum dots (QDs) with amino-functionalized blue fluorescent carbon nanodots (CDs). Under a single excitation wavelength of 365 nm, the sensor exhibits dual-emissions centered at 445 and 603 nm. The fluorescence of CdTe QDs is selectively quenched by DA, whereas the fluorescence of CDs is insensitive to the analyte. In the presence of different amounts of DA, the variations in the dual emission intensity ratios exhibit a...