Browsing Waterloo Institute for Nanotechnology by Author "Zhang, Xu"
Now showing items 1-14 of 14
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Adsorption of DNA Oligonucleotides by Titanium Dioxide Nanoparticles
Zhang, Xu; Wang, Feng; Liu, Biwu; Kelly, Erin Y.; Servos, Mark R.; Liu, Juewen (American Chemical Society, 2014-01-28)Titanium dioxide (TiO2) or titania shows great promise in detoxification and drug delivery. To reach its full potential, it is important to interface TiO2 with biomolecules to harness their molecular recognition function. ... -
Dissecting Colloidal Stabilization Factors in Crowded Polymer Solutions by Forming Self-Assembled Monolayers on Gold Nanoparticles
Lang, Nathan J.; Liu, Biwu; Zhang, Xu; Liu, Juewen (American Chemical Society, 2013-05-21)An ideal colloidal system should be highly stable in a diverse range of buffer conditions while still retaining its surface accessibility. We recently reported that dispersing citrate-capped gold nanoparticles (AuNPs) in ... -
DNA Adsorption by ZnO Nanoparticles near Its Solubility Limit: Implications for DNA Fluorescence Quenching and DNAzyme Activity Assays
Ma, Lingzi; Liu, Biwu; Huang, Po-Jung Jimmy; Zhang, Xu; Liu, Juewen (American Chemical Society, 2016-06-07)Zinc oxide (ZnO) is a highly important material, and Zn2+ is a key metal ion in biology. ZnO and Zn2+ interconvert via dissolution and hydrolysis/condensation. In this work, we explore their interactions with DNA, which ... -
DNA-Functionalized Gold Nanoparticles in Macromolecularly Crowded Polymer Solutions
Zhang, Xu; Liu, Juewen; Shin, Jeehae (American Chemical Society, 2012-11-15)DNA-functionalized gold nanoparticles (AuNPs) are one of the most commonly used reagents in nanobiotechnology. They are important not only for practical applications in analytical chemistry and drug delivery, but also for ... -
Effects of Polyethylene Glycol on DNA Adsorption and Hybridization on Gold Nanoparticles and Graphene Oxide
Zhang, Xu; Huang, Po-Jung Jimmy; Servos, Mark R.; Liu, Juewen (American Chemical Society, 2012-10-09)Understanding the interface between DNA and nanomaterials is crucial for rational design and optimization of biosensors and drug delivery systems. For detection and delivery into cells, where high concentrations of cellular ... -
Fast pH-assisted functionalization of silver nanoparticles with monothiolated DNA
Zhang, Xu; Servos, Mark R.; Liu, Juewen (Royal Society of Chemistry, 2012-10-18)Attaching monothiolated DNA to silver nanoparticles has been achieved at pH 3.0 in 30 minutes and difficulties associated with DNA attachment to AgNPs at neutral pH have been revealed by studying DNA adsorption kinetics. -
Instantaneous and Quantitative Functionalization of Gold Nanoparticles with Thiolated DNA Using a pH-Assisted and Surfactant-Free Route
Zhang, Xu; Servos, Mark R.; Liu, Juewen (American Chemical Society, 2012-05-02)The attachment of thiolated DNA to gold nanoparticles (AuNPs) has enabled many landmark works in nanobiotechnology. This conjugate chemistry is typically performed using a salt-aging protocol where, in the presence of an ... -
Instantaneous Attachment of an Ultrahigh Density of Nonthiolated DNA to Gold Nanoparticles and Its Applications
Zhang, Xu; Dave, Neeshma; Servos, Mark R.; Liu, Juewen; Liu, Biwu (American Chemical Society, 2012-12-11)The last 16 years have witnessed the landmark development of polyvalent thiolated DNA-functionalized gold nanoparticles (AuNP's) possessing striking properties within the emerging field of nanobiotechnology. Many novel ... -
Mechanisms of DNA Sensing on Graphene Oxide
Liu, Biwu; Sun, Ziyi; Zhang, Xu; Liu, Juewen (American Chemical Society, 2013-08-20)Adsorption of a fluorophore-labeled DNA probe by graphene oxide (GO) produces a sensor that gives fluorescence enhancement in the presence of its complementary DNA (cDNA). While many important analytical applications have ... -
Parts-per-Million of Polyethylene Glycol as a Non-Interfering Blocking Agent for Homogeneous Biosensor Development
Liu, Biwu; Huang, Po-Jung Jimmy; Zhang, Xu; Wang, Feng; Pautler, Rachel; Ip, Alexander C-F.; Liu, Juewen (American Chemical Society, 2013-11-05)Many homogeneous assays are complicated by the adsorption of probe molecules by the surface of reaction vessels, which are often made of polypropylene or polystyrene-based plastics. To solve this problem, many protein and ... -
Polarity Control for Nonthiolated DNA Adsorption onto Gold Nanoparticles
Zhang, Xu; Liu, Biwu; Servos, Mark R.; Liu, Juewen (American Chemical Society, 2013-05-21)Gold nanoparticles (AuNPs) functionalized with thiolated DNA have enabled many studies in nanoscience. The strong thiol/gold affinity and the nanoscale curvature of AuNPs allow the attached DNA to adapt an upright conformation ... -
Surface Science of DNA Adsorption onto Citrate-Capped Gold Nanoparticles
Zhang, Xu; Servos, Mark R.; Liu, Juewen (American Chemical Society, 2012-02-28)Single-stranded DNA can be adsorbed by citrate capped gold nanoparticles (AuNPs), resulting in increased AuNP stability, which forms the basis of a number of biochemical and analytical applications, but the fundamental ... -
Toward Fast and Quantitative Modification of Large Gold Nanoparticles by Thiolated DNA: Scaling of Nanoscale Forces, Kinetics, and the Need for Thiol Reduction
Zhang, Xu; Gouriye, Tony; Göeken, Kristian; Servos, Mark R.; Gill, Ron; Liu, Juewen (American Chemical Society, 2013-08-01)We have recently reported on the fast and quantitative adsorption of DNA to 13 nm gold nanoparticles (AuNPs) at pH 3. This is in contrast to most traditional methods at neutral pH, where the adsorption is both slow and ... -
Ultrahigh Nanoparticle Stability against Salt, pH, and Solvent with Retained Surface Accessibility via Depletion Stabilization
Zhang, Xu; Servos, Mark R.; Liu, Juewen (American Chemical Society, 2012-06-20)For many applications, it is desirable to stabilize colloids over a wide range of buffer conditions while still retaining surface accessibility for adsorption and reaction. Commonly used charge or steric stabilization ...