Browsing University of Waterloo by Author "Liu, Biwu"
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Accelerating peroxidase mimicking nanozymes using DNA
Liu, Biwu; Liu, Juewen (Royal Society of Chemistry, 2015-09-07)DNA-capped iron oxide nanoparticles are nearly 10-fold more active as a peroxidase mimic for TMB oxidation than naked nanoparticles. To understand the mechanism, the effect of DNA length and sequence is systematically ... -
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. ... -
Attaching DNA to Nanoceria: Regulating Oxidase Activity and Fluorescence Quenching
Pautler, Rachel; Kelly, Erin Y.; Huang, Po-Jung Jimmy; Cao, Jing; Liu, Biwu; Liu, Juewen (American Chemical Society, 2013-08-14)Cerium oxide nanoparticles (nanoceria) have recently emerged as a nanozyme with oxidase activity. In this work, we present a few important interfacial properties of nanoceria. First, the surface charge of nanoceria can be ... -
Boosting the oxidase mimicking activity of nanoceria by fluoride capping: rivaling protein enzymes and ultrasensitive F- detection
Liu, Biwu; Huang, Zhicheng; Liu, Juewen (Royal Society of Chemistry, 2016-07-28)Nanomaterial-based enzyme mimics (nanozymes) are currently a new forefront of chemical research. However, the application of nanozymes is limited by their low catalytic activity and low turnover numbers. Cerium dioxide ... -
Cation-Size-Dependent DNA Adsorption Kinetics and Packing Density on Gold Nanoparticles: An Opposite Trend
Liu, Biwu; Kelly, Erin Y.; Liu, Juewen (American Chemical Society, 2014-11-11)The property of DNA is strongly influenced by counterions. Packing a dense layer of DNA onto a gold nanoparticle (AuNP) generates an interesting colloidal system with many novel physical properties such as a sharp melting ... -
Characterization of glucose oxidation by gold nanoparticles using nanoceria
Lang, Nathan J.; Liu, Biwu; Liu, Juewen (Elsevier, 2014-04-30)Gold nanoparticles (AuNPs) can oxidize glucose, producing hydrogen peroxide and gluconic acid, which are the same products as those generated by glucose oxidase (GOx). In this regard, AuNPs are a nanozyme. Herein, a new ... -
Comparison of Graphene Oxide and Reduced Graphene Oxide for DNA Adsorption and Sensing
Lu, Chang; Huang, Po-Jung Jimmy; Liu, Biwu; Ying, Yibin; Liu, Juewen (American Chemical Society, 2016-10-18)Fluorescently labeled DNA adsorbed on graphene oxide (GO) is a well-established sensing platform for detecting a diverse range of analytes. GO is a loosely defined material and its oxygen content may vary depending on the ... -
A Comprehensive Screen of Metal Oxide Nanoparticles for DNA Adsorption, Fluorescence Quenching, and Anion Discrimination
Liu, Biwu; Liu, Juewen (American Chemical Society, 2015-10-22)Although DNA has been quite successful in metal cation detection, anion detectioin remains challenging because of the charge repulsion. Metal oxides represent a very important class of materials, and different oxides might ... -
Correlation of photobleaching, oxidation and metal induced fluorescence quenching of DNA-templated silver nanoclusters
Morishita, Kiyoshi; MacLean, James L.; Liu, Biwu; Jiang, Hui; Liu, Juewen (Royal Society of Chemistry, 2013-04-07)Few-atom noble metal nanoclusters have attracted a lot of interest due to their potential applications in biosensor development, imaging and catalysis. DNA-templated silver nanoclusters (AgNCs) are of particular interest ... -
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 Indium Tin Oxide (ITO) Nanoparticles
Liu, Biwu; Liu, Juewen (American Chemical Society, 2015-01-13)The high conductivity and optical transparency of indium tin oxide (ITO) has made it a popular material in the electronic industry. Recently, its application in biosensors is also explored. To understand its biointerface ... -
DNA adsorption by magnetic iron oxide nanoparticles and its application for arsenate detection
Liu, Biwu; Liu, Juewen (Royal Society of Chemistry, 2014-05-01)Iron oxide nanoparticles adsorb fluorescently labeled DNA oligonucleotides via the backbone phosphate and quench fluorescence. Arsenate displaces adsorbed DNA to increase fluorescence, allowing detection of arsenate down ... -
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/Metal Oxide Nanoconjugates: Fundamental Understandings and Analytical Applications
Liu, Biwu (University of Waterloo, 2016-07-29)DNA-functionalized nanomaterials have shown versatile applications in biosensor development, biomedical diagnostics, therapy, and catalysis. DNA is attractive for this purpose for its programmable structure, molecular ... -
Fluorescent sensors using DNA-functionalized graphene oxide
Liu, Zhenbao; Liu, Biwu; Ding, Jinsong; Liu, Juewen (Springer, 2014-07-02)In the past few years, graphene oxide (GO) has emerged as a unique platform for developing DNA-based biosensors, given the DNA adsorption and fluorescence-quenching properties of GO. Adsorbed DNA probes can be desorbed ... -
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 ... -
Intracellular Detection of ATP Using an Aptamer Beacon Covalently Linked to Graphene Oxide Resisting Nonspecific Probe Displacement
Liu, Zhenbao; Chen, Shanshan; Liu, Biwu; Wu, Jianping; Zhou, Yanbin; He, Lingyun; Ding, Jinsong; Liu, Juewen (American Chemical Society, 2014-12-16)Fluorescent aptamer probes physisorbed on graphene oxide (GO) have recently emerged as a useful sensing platform. A signal is generated by analyte-induced probe desorption. To address nonspecific probe displacement and the ... -
Iron oxide nanozyme catalyzed synthesis of fluorescent polydopamine for light-up Zn2+ detection
Liu, Biwu; Han, Xiao; Liu, Juewen (Royal Society of Chemistry, 2016-07-29)Fluorescent polydopamine (FPD) is an interesting material with excellent biocompatibility. However, its preparation is currently a lengthy and potentially dangerous process. We herein employ magnetic iron oxide (Fe3O4) ... -
Magnetic Iron Oxide Nanoparticle Seeded Growth of Nucleotide Coordinated Polymers
Liang, Hao; Liu, Biwu; Yuan, Qipeng; Liu, Juewen (American Chemical Society, 2016-06-22)The introduction of functional molecules to the surface of magnetic iron oxide nanoparticles (NPs) is of critical importance. Most previously reported methods were focused on surface ligand attachment either by physisorption ... -
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 ...