Development of homogeneous binding assays based on fluorescence resonance energy transfer between quantum dots and Alexa Fluor fluorophores.
AuthorsNikiforov TT, Beechem JM
JournalAnal Biochem
PubMed ID16860286
'We studied the fluorescence resonance energy transfer (FRET) between quantum dots emitting at 565, 605, and 655 nm as energy donors and Alexa Fluor fluorophores with absorbance maxima at 594, 633, 647, and 680 nm as energy acceptors. As a first step, we prepared covalent conjugates between all three types ... More
Quantum dot targeting with lipoic acid ligase and HaloTag for single-molecule imaging on living cells.
AuthorsLiu DS, Phipps WS, Loh KH, Howarth M, Ting AY,
JournalACS Nano
PubMed ID23181687
'We present a methodology for targeting quantum dots to specific proteins on living cells in two steps. In the first step, Escherichia coli lipoic acid ligase (LplA) site-specifically attaches 10-bromodecanoic acid onto a 13 amino acid recognition sequence that is genetically fused to a protein of interest. In the second ... More
Imaging a single quantum dot when it is dark.
AuthorsKukura P, Celebrano M, Renn A, Sandoghdar V,
JournalNano Lett
PubMed ID18671437
'We have succeeded in recording extinction images of individual cadmium selenide quantum dots at ambient condition. This is achieved by optimizing the interference between the light that is coherently scattered from the quantum dot and the reflection of the incident laser beam. The ability to interrogate the dot in the ... More
Real-time imaging of astrocyte response to quantum dots: in vivo screening model system for biocompatibility of nanoparticles.
AuthorsMaysinger D, Behrendt M, Lalancette-Hébert M, Kriz J
JournalNano Lett
PubMed ID17638392
Astrocytes are the principle macroglial brain cells. They are activated by different stressors and brain injuries. Quantum dots (QDs) can cause oxidative stress. This study shows a real-time imaging of primary cortical cultures and assessment of QD-induced activation of astrocytes in the brains of transgenic mice with the luciferase gene ... More
Variables influencing interactions of untargeted quantum dot nanoparticles with skin cells and identification of biochemical modulators.
AuthorsRyman-Rasmussen JP, Riviere JE, Monteiro-Riviere NA
JournalNano Lett
PubMed ID17408303
Skin cells (NHEK) take up untargeted quantum dots (QD) with surface polyethylene glycol (PEG), amines, and carboxylic acids, but the mechanisms are unknown. Time courses of QD-NHEK interactions were determined and effects of QD surface coating, temperature, culture medium supplements and inhibitors of the cell cycle and endocytosis identified. The ... More
Optical coding of mammalian cells using semiconductor quantum dots.
AuthorsMattheakis LC, Dias JM, Choi YJ, Gong J, Bruchez MP, Liu J, Wang E
JournalAnal Biochem
PubMed ID15051536
Cell-based assays are widely used to screen compounds and study complex phenotypes. Few methods exist, however, for multiplexing cellular assays or labeling individual cells in a mixed cell population. We developed a generic encoding method for cells that is based on peptide-mediated delivery of quantum dots (QDs) into live cells. ... More
Surface coatings determine cytotoxicity and irritation potential of quantum dot nanoparticles in epidermal keratinocytes.
AuthorsRyman-Rasmussen JP, Riviere JE, Monteiro-Riviere NA
JournalJ Invest Dermatol
PubMed ID16902417
Quantum dot (QD) nanoparticles have potential applications in nanomedicine as drug delivery vectors and diagnostic agents, but the skin toxicity and irritation potential of QDs are unknown. Human epidermal keratinocytes (HEKs) were used to assess if QDs with different surface coatings would cause differential effects on HEK cytotoxicity, proinflammatory cytokine ... More
Penetration of intact skin by quantum dots with diverse physicochemical properties.
AuthorsRyman-Rasmussen JP, Riviere JE, Monteiro-Riviere NA
JournalToxicol Sci
PubMed ID16443688
Skin is the largest organ of the body and is a potential route of exposure to engineered nanomaterials, but the permeability of the skin to these nanomaterials is unknown. We selected commercially available quantum dots (QD) of two core/shell sizes and shapes and three different surface coatings to determine if ... More
Qdot nanobarcodes for multiplexed gene expression analysis.
AuthorsEastman PS, Ruan W, Doctolero M, Nuttall R, de Feo G, Park JS, Chu JS, Cooke P, Gray JW, Li S, Chen FF
JournalNano Lett
PubMed ID16683851
We report a quantum dot (Qdot) nanobarcode-based microbead random array platform for accurate and reproducible gene expression profiling in a high-throughput and multiplexed format. Four different sizes of Qdots, with emissions at 525, 545, 565, and 585 nm are mixed with a polymer and coated onto the 8-mum-diameter magnetic microbeads ... More