DNA Monofunctionalization of Quantum Dots

Abstract

Dots as pure as the driven snow: A method to purify streptavidin‐coated quantum dots functionalized with a single short DNA duplex from an inhomogeneous population is presented. A high percentage (∼86 %) of the monofunctionalized quantum dots present in the original sample are recovered. Hybridization of the attached DNA after purification is demonstrated.

Biotin-4-Fluorescein Based Fluorescence Quenching Assay for Determination of Biotin Binding Capacity of Streptavidin Conjugated Quantum Dots

“…(48) Our lab, as well as other laboratories, previously reported using gel electrophoresis to determine the extent of conjugation of a given batch of QD conjugates. 17,18,28,30,35−38,52 However, these methods are material and time intensive and infer conjugation from size rather than directly measuring bioactivity. Lastly, the multiplate assay format requires smaller sample volumes, consuming <4% of the commercially provided material for a triplicate analysis of the biotin binding capacity.…”

Formation of targeted monovalent quantum dots by steric exclusion

“…After transfer of commercial CdSe:ZnS QDs from the organic to the aqueous phase, we treated the QDs with ptDNA of various sequences and lengths. DNA-functionalization produced QDs with an ionic character that were easily distinguishable from unfunctionalized QDs by agarose gel electrophoresis 8,15 . We titrated 605 nm emitting QDs (605-QDs) with increasing concentrations of an oligonucleotide comprising a 50 adenosine ptDNA domain (A S 50 ) and a 20 nucleotide ssDNA targeting tail (Fig.…”

Overcoming the Coupling Dilemma in DNA‐Programmable Nanoparticle Assemblies by “Ag+ Soldering”

“…Since the nanoparticle coupling is controlled by proximity, it should also be possible to accurately define a specific nanoparticle pair to be soldered within a complex multiparticle system. By combining the developments in structural DNA nanotechnology and taking advantage of the much enriched DNA‐monofunctionalized nanomaterials developed in recent years, the DNA‐programmable Ag + soldering is expected to deliver some innovative optical, electronic, optoelectronic, and catalytic applications in the near future.…”