رسائل دكتوراة
English
2023
Implementation of Electro-Plasmonics Chip for Detection Alzheimer Disease
حسام جواد كاظم عبود الجنابي, حسين هادي ناهي, حيدر صاحب المؤمن
كلية الهندسة-جامعة بابل · العراق
The human brain contains of billions of neurons that control the central nervous system. Many techniques have been used for recording neural signals and mapping such as EEG (electroencephalogram), MEG (Magnetoencephalography), MRI (Magnetic Resonance Imaging), fMRI(Functional magnetic resonance imaging), CT scan(computed tomography), and fiber-optic techniques...etc. The recording of neuronal activity with low spatial and millisecond temporal resolutions at arbitrary depths in the brain tissues is the most difficult challenge for all of that methods. Therefore, these challenges required novel neural recording techniques in the fields of optics, electronics, magnetics, and other technologies to increase the spatial and millisecond temporal resolutions.One of the modern technologies for sensing neuron activity with high spatial and millisecond temporal resolutions is the plasmonics technique. This technology uses surface plasmon resonance(SPR) sensing to detect neuron activity. Using plasmonics technology with neuron sensing is called Neuro plasmonics technology. This technology combines biosensing with nanotechnologies in both in-vitro and in-vivo conditions. Furthermore, it is providing advantages such aslabel-free detection, real-time analysis, Biocompatible,small sample, low detection limit, and high throughput.In this thesis, an electro-plasmonic chip has been fabricated. It consists of grading layers of polycarbonate as a dielectric coated by a thin layer of gold (35nm). The prepared chip is connected with two terminals (wires) to apply an external voltage and then induce a one-dimensional (1D) electro-plasmonic nanograting chip. The fabricated chip has been evaluated physically by use of a suitable setup and then evaluated biologically to sense a different concentration of dopamine. The second step was to culture the electro-plasmonic chip with neuron cells extracted from rats and stimulated
IIby dopamine. This step was to evaluate the ability of the electro-plasmonic chip for detecting the activity of cultured neuron cells. Finally, the electro-plasmonic chip was cultured with human nucleus pulposus cells(HNPC) and then injected with streptozotocin (STZ). This step was to evaluate the ability of the proposed chip for sensing the inhibition of the cultured neuron cells. The results show a nice physical phenomenon known as a plasmonic induce transparency (PIT). This physical phenomenon is produced by surface plasmon resonance (SPR) and it is proper for sensing neuron activity. By applying an external DC voltage, the amplitude (light intensity) increased, which means generating at unable plasmon-induced transparency. The generating of tunable PIT means increasing the proposed chip sensitivity. The proposed chip shows excellent results for sensing different concentrations of dopamine (300 and 700 ppm). A very clear difference was observed in the amplitude of concentration at the wavelength range of 580nm to 600nm. In the next step, twelve samples were cultured with neuron cells (rats) and then stimulated by different concentrations of dopamine. The results show the high ability of the proposed chip for sensing the neuron cells’ activity with high concentration (700ppm) and low concentration about 0.5ppm. Also, the high sensitivity with low concentration at the time range of 2 –10 min. Lastly, the proposed chips (8 samples) were cultured with HNPC cells and injected with Streptozotocin (STZ) in three different concentrations (0.5, 1, and 2 mM). This step was to induce Alzheimer’s disease and to measure the cell’s inhibition. The results show the cell’s activity decreased (inhibition) with increasing the STZ dose. These indicate the high sensitivity of the electro-plasmonic chip for sensing the cultured neuron cells’ activity.