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Sapsford K.E.,U.S. Food and Drug Administration | Algar W.R.,George Mason University | Algar W.R.,University of British Columbia | Berti L.,University of California at Davis | And 6 more authors.
Chemical Reviews | Year: 2013

Bionanotechnology has now become firmly established in its own right as one of the principle and focused subdisciplines within nanotechnology. Bionanotechnology can be defined as a field representing all facets of research at the intersection of biology and nanomaterials (NM) and is generally characterized as having two somewhat opposite functional goals. The interest in using NMs, and especially NPs, as part of biomolecular composites arises from the unique size-dependent physical, optical, electronic, and chemical properties that they can contribute to the resulting conjugate. These may include quantum confined properties as typified by the size-tunable photoluminescence (PL) of nanocrystalline semiconductor quantum dots (QD), the plasmon resonances of gold NPs, the electrical properties of carbon allotrope NMs, and the paramagnetism and catalytic properties available to certain metal alloy and metal oxide NPs.

Blanco-Canosa J.B.,Scripps Research Institute | Blanco-Canosa J.B.,Barcelona Institute for Research in Biomedicine | Wu M.,University of British Columbia | Susumu K.,U.S. Navy | And 6 more authors.
Coordination Chemistry Reviews | Year: 2014

The utility of luminescent semiconductor quantum dots (QDs) in biological applications is directly dependent upon their ability to undergo bioconjugation to proteins, peptides, DNA, drugs and indeed all other manner of biomolecules. In this focused review, we provide an overview of the diverse chemistries that are used for these purposes, including a special emphasis on recent progress by our groups toward optimizing or developing new chemistries. We begin by examining the characteristics and activity ideally desired from QD-bioconjugates, along with the linkage chemistries that are most often utilized. The utility of polyhistidine-mediated metal-affinity coordination to QD surfaces or surface functionalizing ligands is then described in detail. This particular conjugation approach is highly desirable due to its functional simplicity and the control it can afford over the final QD-bioassembly. A variety of other modular, chemoselective ligation chemistries that can be applied either directly on the QD or to the biological to facilitate subsequent QD assembly are described, including aniline-catalyzed imine ligation, thiol-exchange, thiol-targeting iodoacetate chemistry, and Cu(I)-catalyzed azide-alkyne cycloaddition. Commercial QD labeling chemistries that incorporate some of these bioconjugation approaches are also highlighted. Due to their continued widespread use, bioconjugation routes that target the QD surface functionalizing and solubilizing ligands are covered, as are improvements in their functional implementation. Selected examples of applications that incorporate QD-bioconjugates assembled using the different chemistries described are included where appropriate, along with discussion of their benefits and liabilities within that application. Finally, a perspective on remaining issues and how this field will evolve is offered. © 2013 Published by Elsevier B.V.

Dennis A.M.,Boston University | Delehanty J.B.,Center for Bio Molecular Science and Engineering Code 6900 | Medintz I.L.,Center for Bio Molecular Science and Engineering Code 6900
Journal of Physical Chemistry Letters | Year: 2016

Efforts to create new nanoparticle-biomolecule hybrids for diverse applications including biosensing, theranostics, drug delivery, and even biocomputation continue to grow at an unprecedented rate. As the composite designs become more sophisticated, new and unanticipated physicochemical phenomena are emerging at the nanomaterial-biological interface. These phenomena arise from two interrelated factors, namely, the novel architecture of nanoparticle bioconjugates and the unique physicochemical properties of their interfacial environment. Here we examine how the augmented functionality imparted by such hybrid structures, including accessing concentric energy transfer, enhanced enzymatic activity, and sensitivity to electric fields, is leading to new applications. We discuss some lesser-understood phenomena that arise at the nanoparticle interface, such as the complex and confounding issue of protein corona formation, along with their unexpected benefits. Overall, understanding these complex phenomena will improve the design of composite materials while uncovering new opportunities for their application. © 2016 American Chemical Society.

Field L.D.,Center for Bio Molecular Science and Engineering Code 6900 | Field L.D.,University of Maryland College Park | Andrasfalvy B.K.,Hungarian Academy of Sciences | Galinanes G.L.,University of Geneva | And 9 more authors.
Progress in Biomedical Optics and Imaging - Proceedings of SPIE | Year: 2015

The simultaneous visualization, identification and targeting of neurons during patch clamp-mediated electrophysiological recordings is a basic technique in neuroscience, yet it is often complicated by the inability to visualize the pipette tip, particularly in deep brain tissue. Here we demonstrate a novel approach in which fluorescent quantum dot probes are used to coat pipettes prior to their use. The strong two-photon absorption cross sections of the quantum dots afford robust contrast at significantly deeper penetration depths than current methods allow. We demonstrate the utility of this technique in multiple recording formats both in vitro and in vivo where imaging of the pipettes is achieved at remarkable depths (up to 800 microns). Notably, minimal perturbation of cellular physiology is observed over the hours-long time course of neuronal recordings. We discuss our results within the context of the role that quantum dot nanoprobes may play in understanding neuronal cell physiology. © 2015 SPIE.

Nagy A.,U.S. Food and Drug Administration | Gemmill K.B.,Center for Bio Molecular Science and Engineering Code 6900 | Delehanty J.B.,Center for Bio Molecular Science and Engineering Code 6900 | Medintz I.L.,Center for Bio Molecular Science and Engineering Code 6900 | Sapsford K.E.,U.S. Food and Drug Administration
IEEE Journal on Selected Topics in Quantum Electronics | Year: 2014

Quantum dot (QD) nanomaterials have a number of electro-optical properties that make them ideal for biosensing applications. QDs combined with peptides have been used for both targeting and sensing applications, however this review will focus specifically on peptide-functionalized QD biosensors, whose signal transduction occurs through active modulation of the QD photoluminescent properties.

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