Nanoparticles have been demonstrated as a promising new generation of specific imaging agents and targeted delivery vehicles for the diagnosis and treatment of solid tumors. Nonetheless, for optimal therapy of tumors, the nanoparticles must penetrate the tumor interstitial matrix to reach the cancer cells. This thesis describes the development of a multiphoton fluorescence correlation spectrosc...

A selective aptasensor was developed using the electrochemical transduction method for the ultrasensitive detection of cocaine. In this method, dendrimer-quantum dot (Den-QD) bioconjugate was utilized as a specific nanocomposite to efficiently fabricate the aptasensor. CdTe QD, which carries highly significant properties, was immobilized on the surface of a glassy carbon electrode (GCE), and po...

The one photon absorption (OPA) cross section of a current carrying two-orbital quantum dot (QD) with strong electron-phonon interaction (polaron regime) is considered. Using the self-consistent non-equilibrium Hartree-Fock (HF) approximation, we determine the dependence of OPA cross section on the applied bias voltage, the strength of effective electron-electron interaction, and level spacing ...

We describe the preparation, biophysical characterization, and receptor-mediated cellular internalization of biotinylated lipid particles (BLPs) loaded on the surface and internally with two distinct (colors) of quantum dot (QD) probes. BLPs were formulated with 1.4 and 2.7 mol % PEG-lipids containing either a fusogenic or pH-sensitive lipid to promote bilayer destabilization of endosomal membr...

We investigate the mechanism of operation of hybrid organic/colloidal quantum dot light emitting devices QD-LEDs . Novel quantum dot QD deposition methods allow us to change the location of an emissive QD monolayer within a QD-LED multilayer structure. We find that the quantum efficiency of devices improves by 50% upon imbedding QD monolayers into the hole transporting layer 10 nm away from the...

BACKGROUND Semiconductor quantum dots (QDs) hold increasing potential for cellular imaging both in vitro and in vivo. In this report, we aimed to evaluate in vivo multiplex imaging of mouse embryonic stem (ES) cells labeled with Qtracker delivered quantum dots (QDs). RESULTS Murine embryonic stem (ES) cells were labeled with six different QDs using Qtracker. ES cell viability, proliferation, ...

Energy loss due to carrier recombination is among the major factors limiting the performance of TiO2/PbS colloidal quantum dot (QD) heterojunction solar cells. In this work, enhanced photocurrent is achieved by incorporating another type of hole-transporting QDs, Zn-doped CuInS2 (Zn-CIS) QDs into the PbS QD matrix. Binary QD solar cells exhibit a reduced charge recombination associated with the...

The electronic properties of colloidal quantum dots (QDs) are critically dependent on both QD size and surface chemistry. Modification of quantum confinement provides control of the QD bandgap, while ligand-induced surface dipoles present a hitherto underutilized means of control over the absolute energy levels of QDs within electronic devices. Here, we show that the energy levels of lead sulfi...

Kondo correlation in a spin polarized quantum dot (QD) results from the dynamical formation of a spin singlet between the dot's net spin and a Kondo cloud of electrons in the leads, leading to enhanced coherent transport through the QD. We demonstrate here significant dephasing of such transport by coupling the QD and its leads to potential fluctuations in a nearby "potential detector." The qua...