The innovation engine for new materials

Jason Tillman

Jason Tillman

Major: 

Chemistry

University: 

University of California Santa Barbara

Mentor(s): 

Peter Burks

Faculty Sponsor(s): 

Professor Peter Ford

Faculty Sponsor's Department(s): 

Chemistry and Biochemistry

Project Title: 

SYNTHESIS OF ZINC SELENIDE QUANTUM DOTS

Project Description: 

Nitric oxide is an endogenous signaling molecule in mammals that plays an important role in vasodilatation and has been shown to increase the effectiveness of radiation treatment.  However, methods that can control the location, timing and dosage of nitric oxide in vivo are lacking.  A promising method for selectively delivering NO to physiological targets uses photoactive nitric oxide releasing molecules (photo-NORMs) which only release NO when excited by light.  However, photo-NORMs primarily absorb in the UV, which is not an ideal range for photo-assisted drug delivery.  Our work focuses on developing ZnSe QDs (quantum dots) that can be attached to photo-NORMs and act as an 'antenna' that efficiently absorbs visible light and transfers that energy to the photo-NORM allowing it to release NO.  QD are an attractive antenna due to their large single and two-photon absorption which allows them to effectively absorb light.  Reported herein are results on the development and optimization of a reproducable single-pot synthesis for violet-emitting ZnSe QDs.  By varying the Zn and Se precursor type and concentration, in addition to the surfactant type and concentration, we developed the following synthetic procedure in which zinc octanoate, selinium dioxide, trioctylphosphine, and 1,2-hexadecanediol are combined in the noncoordinating solvent 1-octadecene and heated to the nucleation temperature where the QDs are formed. The affect of the variance of precursors and surfactants on ZnSe QD photoluminescence in addition to the observed surface oxidation under air and light will be discussed.