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01 February 2012. Detecting single metal nanoparticle by dark-field microscopy. Jeonghoo kim Marian High School. Introduction & Motivation. Results & Analysis. Absorbance Mode.
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01 February 2012 Detecting single metal nanoparticle by dark-field microscopy Jeonghoo kim Marian High School Introduction & Motivation Results & Analysis Absorbance Mode Dark field microscopy describes microscopy method, in both light and electron microscopy, which exclude the unscattered beam of the image. In this experiment, dark field optical microscopy was used to detect single metal nanoparticles. The goals of this research were to develop the technique to observe nano-sized particles and to understand the factors that influence the position and line width of the plasmon band, which is collective motion of the electrons in the particle. The plasmon band gives rise to the brilliant colors of metal particle samples. Solutions ( Ag, Au, Ag with no BSPP), Au: Ag) The picture of the Rose window in the Notre Dame cathedral Paris. Picture of Nanoparticle Au particle Au Ag particle Procedure • Clean the condenser so microscope and give focused picture of particles. • Put the slide with the particles on the microscope stage • Drop a oil on the slide , then focus the particle by adjusting the microscope • Take a picture of the particle by using the camera. • Use the spectrometer to find the plasmon band of each paritlces. Ag particle Ag particle with no BSPP Discussion Inside of the spectrometer that shows the light path. The spectrometer that was used to find the plasmon of each particles Different samples showed different colors . Au particles were expected to be brown. However, they contained more red and yellow particles. The actual colors of particles are different probably because different shapes and size present in the samples. Especially for Ag triangle, there were many different colors. This is one reason nanoparticles need to be studied using a microscope. Conclusions Single nanoparticles of Au, Ag, Au-Ag, Au with no BSPP of ~20nm size were detected The plasmon band is very sensitive to the exact shape of the particles Future Research : change the light path in the microscope so that a spectrometer can be used to measure the plasmon band ( record spectra of individual spectra)