Synthesis and Functionalization of Quantum Dots for Bio Agent Detection

Period of Performance: 01/12/2001 - 07/12/2001


Phase 1 SBIR

Recipient Firm

Biocrystal, Ltd.
575 McCorkle Boulevard
Westerville, OH 43082
Principal Investigator


A new class of fluorescent nanocrystals offers the prospect of replacing organic dyes for many fluorescence detection and analysis schemes commercially in use. BioCrystal has developed a family of proprietary fluorescence-based detection reagents which utilize a semiconductor nanocrystal core(CdSe) encased in a semiconductor(ZnS)shell and one or more organic layers which confer water solubility, as well as reactive sites which may be used to bind molecules such as affinity ligands to the functionalized nanocrystal. They are monodisperse and resist photobleaching.The Phase I work effort will demonstrate the feasibility of the following:(1)the use of a continuous flow production technique to produce monodisperse CdSe nanocrystals (CdSeNC) of uniform size in different colors to industrial proportions;(2)the industrial scale production of water-soluble, functionalized CdSeNC, including the production and purification of avidin-labeled CdSeNC;(3)the conjugation of functionalized CdSeNC to bioreceptors, and their use for detection by FRET or aggregation testing.This work will preface the Phase II objective of developing a procedure for the detection of bio-contaminants using functionalized CdSe nanocrystals, and, in parallel, to produce a miniaturized, autonomous sensor device to perform this procedure under continuous use, or during desired periods of time.Multiplexing, constant emission, particulate structure and energy transfer are inherent characteristics which afford fluorescent CdSe nanocrystals a number of advantages over fluorochromes for use in detecting multiple bio-contaminants in sensor devices, and for a number of other commercial uses: as DNA/RNA probes in qualitative disease detection; viral genotyping; automated biological assays for high throughput screening (HTS) applications in drug discovery; fluorescence-based histological studies, including the identification of cancerous tissue, and as encoded beads in multi-dimensional micro-assay formats.