Andrew K. Boal

Efficient recognition of DNA is a prerequisite for the development of biological effectors, including transcription and translation regulators, transfection vectors, and DNA sensors. To provide an effective scaffold for multivalent interactions with DNA, we have fabricated mixed monolayer protected gold clusters (MMPCs) functionalized with tetraalkylammonium ligands that can interact with the DNA backbone via charge complementarity. Binding studies indicate that the MMPCs and DNA form a charge-neutralized, nonaggregated assembly. The interactions controlling these assemblies are highly efficient, completely inhibiting transcription by T7 RNA polymerase in vitro.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTFabrication and Self-Optimization of Multivalent Receptors on Nanoparticle ScaffoldsAndrew K. Boal and Vincent M. RotelloView Author Information Department of Chemistry University of Massachusetts Amherst Massachusetts 01003 Cite this: J. Am. Chem. Soc. 2000, 122, 4, 734–735Publication Date (Web):January 13, 2000Publication History Received3 November 1999Published online13 January 2000Published inissue 1 February 2000https://doi.org/10.1021/ja993900sCopyright © 2000 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1565Altmetric-Citations148LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (45 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Aromatic compounds,Colloids,Flavins,Noncovalent interactions,Screening assays Get e-Alerts

Nature has evolved dynamic, non-equilibrium mechanisms for assembling hierarchical complexes of nanomaterials. A critical element to many of these assembly mechanisms involves the active and directed transport of materials by biomolecular motor proteins such as kinesin. In the present work, nanocrystal quantum dots (nQDs) were assembled and organized using microtubule (MT) filaments as nanoscale scaffolds. nQD density and localization were systematically evaluated by varying the concentration and distribution of functional groups within the MT structure. Confining nQD attachment to a central region within the MT enabled unaffected interaction with kinesin necessary to support active transport of nQD−MT composites. This active transport system will be further refined to control the optical properties of a surface by regulating the collective organization of nQD−MT composites.

Cationic superparamagnetic iron oxide nanoparticles were assembled using a series of anionic polyamidoamine dendrimers. The resulting assemblies featured systematically increasing average interparticle spacing over a 2.4 nm range with increasing dendrimer generation. This increase in spacing modulated the collective magnetic behavior by effective lowering of the dipolar coupling between particles. The results obtained in these studies deviate from the predicted dependence of collective behavior on interparticle spacing, suggesting that a dense assembly of magnetically "free" particles can exist with a surprisingly small space between particles.