Date

6-2013

Degree Name

BS in Materials Engineering

Department

Materials Engineering Department

Advisor(s)

Richard Savage

Abstract

Fluorescence profiles of quantum dots (QDs) were characterized to select the ideal QDs for encapsulation in phospholipids for use as biomarkers to selectively adhere to cancer cells. QDs were synthesized and extracted 0, 30, 60, and 90 seconds after precursor compounds were mixed. These extractions were isolated by extraction time. Portions from each vial were coated in a zinc sulfide shelling procedure, leaving at least half of the QD solution unshelled. These samples were characterized over four days to monitor fluctuations in fluorescence. This was done utilizing an Ocean Optics spectrometer in conjunction with Spectra Suite software. The central wavelength, maximu intensity, and the full width at half maximum (FWHM) were the main focus of the measurements. Ten measurements were taken on each sample at Days 0 (the day of the shelling procedure), 1, and 3. On Day 0, shelled QDs showed significant shifts in central fluorescence wavelength, increases in intensity, and minor increase to FWHM. Over the span of the following 3 days, the unshelled QD’s maintained their central wavelength, relative peak intensity, and FWHM. The central wavelength and FWHM of the shelled quantum dots remained stable after the initial shift as well. In contrast, the shelled quantum dots intensity continued to increase the day after the shelling process, often increasing into the fourth day of characterization. This is likely due to reactants in the solution continuing to bond to the QDs. The higher intensity, shelled quantum dots will be encapsulated with phospholipids for use as biomarkers.