Loading...
Search for: dopamine
0.063 seconds

    , M.Sc. Thesis Sharif University of Technology Mahdavi Shakib, Akbar (Author) ; Shahrokhian, Saeed (Supervisor)
    Abstract

    This experimental work is of two parts. First, self-assembled monolayers of cysteamine was formed on the gold electrode surface which leaded to the formation of amine groups on the surface; then amine bond was formed between these amine groups and the carboxylic acid groups of acid treated multi-walled carbon nanotubes (MWCNTs). The modified electrode was used for voltammetric determination of dopamine in the presence of uric acid. In the second part, acid treated MWCNTs were decorated with ruthenium nanoparticles; then the resulting composite was used for surface modification with the exact same procedure as the first part. Ruthenium nanoparticles on the electrode surface were... 

    Fabrication of a Sensor, Based on TiO2 Nanotubes Modified with Metal Nanoparticles and Carbon and its Application for Detection of Dopamine in Presence of Uric Acid and Ascorbic Acid

    , Ph.D. Dissertation Sharif University of Technology Mahshid, Sara (Author) ; Askari, Masoud (Supervisor) ; Dolati, Abolghasem (Supervisor)
    Abstract
    The present work describes sensing application of modified TiO2 nanotubes towards detection of dopamine. The TiO2 nanotubes electrode was prepared using anodizing method at different conditions, among which NaF/ NaHSO4 solution and voltage of 15 V was chosen as the optimum condition. In order to improve the performance, surface modification with metal nanoparticles (Pd, Pt and Au) and carbon is required using “pulse electrodeposition” and “decomposition of polyethylene glycol at 600 °C” respectively. Carbon was deposited by decomposition of polyethylene glycol in a tube furnace to improve the conductivity. In this regard two type of electrodes were proposed: Pd-Pt-Au-TiO2 and C-Ni(Pt)-TiO2.... 

    Synthesis and Study of Electron Transport through a Self-Assembled Monolayer of Thiol-End-Functionalized Tetraphenylporphyrines and Metalo-Tetraphenylporphyrines and Electrochemical Analysis of Dopamine and Ascorbic Acid with this SAMs

    , M.Sc. Thesis Sharif University of Technology Sanaei, Mahsa (Author) ; Mohammadi Boghaei, Davar (Supervisor)
    Abstract
    Self-Assembled Monolayer (SAM) is the first step in all surface engineering and assembly processes. It is used in sensor fabrication, memories and molecular recognition and optoelectronic devises as an active surface for patterning and chemical architecting of solid substrates. Tetraphenyl porphyrins because of their high stability and uniqe electronic and optic properties, that comes from their conjugate π electrons, easily can be used in these monolayers. Moreover they have a wide application because of their ability for coordination with metals and accepting substituents with electron donating and withdrawing properties. Electron transport through these layars which attach to the surface... 

    Development of Ratiometric Sensors Based on Fluorescent Nanostructures for Naked Eye Detection

    , Ph.D. Dissertation Sharif University of Technology Farahmand Nejad, Mohammad Amin (Author) ; Hormozi-Nezhad, Mohammad Reza (Supervisor)
    Abstract
    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... 

    Development of a Multi-Colorimetric Sensor Based on Anti-Etching of Gold Nanorods for Simultaneous Detection and Determination of Neuroblastoma Tumor Biomarkers

    , M.Sc. Thesis Sharif University of Technology Miri, Amir Hossein (Author) ; Hormozi Nezhad, Mohammad Reza (Supervisor)
    Abstract
    The detection and on-site measurement of vanillylmandelic acid (VMA), homovanillic acid (HVA), and dopamine (DA) as key biomarkers for a wide range of neurological disorders, including neuroblastoma, is of significant importance. To date, several colorimetric sensors have been introduced with mechanisms based on nanoparticle aggregation or their coating with silver. However, these mechanisms have drawbacks such as sensitivity to environmental factors and probe toxicity. Therefore, there is a high demand for a robust and non-toxic colorimetric sensor that utilizes a novel approach for the effective monitoring of these biomarkers. In this study, a single-component multicolor probe was designed...