DOCSLIB.ORG

PLASMON EXCITON INTERACTION in GOLD NANOSTRUCTURES and QUANTUM DOT CONJUGATE and ITS APPLICATION in BIOSENSOR ZHANG TAO (B. Eng

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
PLASMON EXCITON INTERACTION in GOLD NANOSTRUCTURES and QUANTUM DOT CONJUGATE and ITS APPLICATION in BIOSENSOR ZHANG TAO (B. Eng PLASMON EXCITON INTERACTION IN GOLD NANOSTRUCTURES AND QUANTUM DOT CONJUGATE AND ITS APPLICATION IN BIOSENSOR ZHANG TAO (B. Eng.) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF CHEMICAL AND BIOMOLECULAR ENGINEERING NATIONAL UNIVERSITY OF SINGAPORE 2013 Declaration I Acknowledgements I would like to express my gratitude to all of those who have helped and inspired me during my four year doctoral study. My utmost thankfulness goes to my advisor, Prof. Chen Shing Bor for his patient guidance and selfless encouragement in my research and study at National University of Singapore. His exceptional intuition in physics and persistent desire for high quality research has motivated all his advisees, including me. I would like to thank my co-supervisor Prof. Lanry Yung Lin Yue for his guidance. I would like to thank my thesis committee, Prof. Zeng Huachun and Prof. Lu Xianmao for taking their precious time attending my thesis defense. My thanks also go to my previous and current labmates, Dr. Chieng Yuyuan, Dr. Ma Ying, MS Ang Yan Shan for their help during my study. My deepest gratitude goes to my family for their unflagging love and support throughout my life, especially my wife Wei Xiaowei whose fully support enables me to complete the work. In the last, I would like to thank all the funding agencies. This work is supported Ministry of Education, Singapore. II Table of Contents Declaration ................................................................................................................. I Acknowledgements .................................................................................................. II Table of Contents .................................................................................................... III Summary ................................................................................................................. VI List of Tables .......................................................................................................... IX List of Figures .......................................................................................................... X List of Symbols ...................................................................................................XVII Chapter 1 Introduction .............................................................................................. 1 Chapter 2 Literature Review ..................................................................................... 9 2.1 Plasmon-enhanced luminescence near noble metal nanostructures ........................ 9 2.2 Biosensing with plasmonic nanosensors. .............................................................. 12 2.3 Surface-enhanced Raman Scattering (SERS) based on plasmonic materials ....... 15 Chapter 3 Material Synthesis and Characterization ................................................ 20 3.1. Introduction .......................................................................................................... 20 3.2. Experimental Section ........................................................................................... 23 3.2.1 Synthesis of SAuNP with diameter of 11 nm, 25 nm, and 45 nm ..................... 23 3.2.2 Preparation of gold nanorod (AuNR) with aspect ratio of 3.5 ........................... 24 3.2.3 Synthesis of popcorn-shaped gold nanoparticles (PS-AuNP) ............................ 26 3.2.4 Functionalizing SAuNP with thiol and carboxyl-modified polyethelyene glycol (SH-PEG-COOH) via ligand exchange ...................................................................... 27 3.2.5 Two phase ligand exchange for AuNR and PS-AuNP....................................... 27 3.2.6 Conjugation of AuNP with QD to form AuNP-QD Nanoconjugates ................ 29 3.2.7 Characterization methods ................................................................................... 29 III 3.3 Results and Discussion ......................................................................................... 30 3.3.1. Spherical Gold nanoparticle and quantum dots conjugate (SAuNP-QD) ......... 30 3.3.2. Gold nanorod (AuNR) and quantum dot (QD) conjugate (AuNR-QD) ........... 35 3.3.3. Popcorn-shaped Gold Nanoparticles (PS-AuNP) and quantum dots (QDs) conjugate. .................................................................................................................... 40 3.4. Conclusion ........................................................................................................... 44 Chapter 4 Plasmon-Exciton Interactions in Single AuNP-QD conjugate: Correlating Modeling with Experiments................................................................. 46 4.1. Introduction .......................................................................................................... 46 4.2 Experiment section................................................................................................ 49 4.2.1 Characterization methods ................................................................................... 49 4.2.2. Finite-Difference Time-Domain (FDTD) modeling ......................................... 50 4.3 Results and Discussion ......................................................................................... 51 4.3.1 Steady-state photoluminescence properties of AuNP-QDs ............................... 51 4.3.2 FDTD simulation and electrodynamics calculation of PS-AuNP-QD system ... 57 4.3.3 Scattering properties of single SAuNP-QDs, AuNR-QDs and PS-AuNP-QD system ......................................................................................................................... 62 4.4 Conclusion ............................................................................................................ 81 Chapter 5 Protein Detection Based on PS-AuNP-QD Conjugate ........................... 85 5.1 Introduction ........................................................................................................... 85 5.2 Experiment Section ............................................................................................... 88 5.2.1 Synthesis of Biotinylated PS-AuNP-QD ........................................................... 88 5.2.2 Avidin Detection Based on Biotinylated PS-AuNP-QD .................................... 89 5.2.3 Attachment of Immunoglobulin G (IgG) onto the Surface of PS-AuNP-QD .... 89 5.2.4 E. Coli Bacteria Detection Based on PS-AuNP-QD-IgG .................................. 90 IV 5.3 Results and Discussions ........................................................................................ 90 5.3.1 Avidin Detection Based on Biotinylated PS-AuNP-QD .................................... 90 5.3.2 E. Coli Bacteria Detection Based on PS-AuNP-QD-IgG .................................. 95 5.4 Conclusion ............................................................................................................ 99 Chapter 6 Strong Surface-Enhanced Raman Scattering Signals of Analytes Attached on PS-AuNP-QD and the Application in Protein Structure Studies ...... 101 6.1 Introduction ......................................................................................................... 101 6.2 Experiment Section ............................................................................................. 104 6.2.1 Functionalizing PS-AuNPs with Thiotic Acid (TA) and 4-Mercaptobenzonic Acid (4-MBA) via Ligand Exchange ........................................................................ 104 6.2.2 Surface-enhanced Raman spectroscopy for 4-MBA attached on PS-AuNP-QD .................................................................................................................................. 104 6.2.3 Characterization Methods ................................................................................ 105 6.3 Results and Discussions ...................................................................................... 106 6.3.1 SERS spectrum of 4-MBA attached on PS-AuNP-QD.................................... 106 6.3.2 The application of PS-AuNP-QD in avidin structure study ............................. 109 6.4 Conclusion .......................................................................................................... 112 Chapter 7 Conclusion and Future Work ............................................................... 115 V Summary Plasmon Exciton Interaction in Gold Nanostructure and Quantum Dot Conjugate and its Applications in Biosensor By Zhang Tao By synthesizing gold nanostructure (AuNP) and quantum dot (QD) conjugates, we investigated the optical properties of this type of conjugates both experimentally and theoretically. Also, the potential applications of the conjugates in protein detection and surface-enhanced Raman scattering (SERS) were also explored. We synthesized three different sizes of spherical AuNPs (SAuNPs) (11 nm, 25 nm and 45 nm), and then functionalized them with carboxyl groups via ligand exchange. The amine-functionalized QDs can be reacted with SAuNPs and form amide bond between them. Dark field microscopy was employed to examine the single particle optical properties of this SAuNP-QD conjugate. The scattering spectra of SAuNP-QDs shows coupled modes between exciton and plasmon. According to our numerical simulation using finite-difference time-domain (FDTD) method, we also found that the interaction between SAuNP and QD depends on the polarization of the excitation light. Besides, the interaction between exciton and plasmon also affects the
Load more

Recommended publications
  • First-Principles and Molecular Dynamics Simulation Studies of Functionalization of Au32 Golden Fullerene with Amino Acids
    www.nature.com/scientificreports OPEN First-principles and Molecular Dynamics simulation studies of functionalization of Au32 golden Received: 4 August 2017 Accepted: 18 July 2018 fullerene with amino acids Published: xx xx xxxx M. Darvish Ganji1, H. Tavassoli Larijani2, R. Alamol-hoda1 & M. Mehdizadeh1 With the growing potential applications of nanoparticles in biomedicine especially the increasing concerns of nanotoxicity of gold nanoparticles, the interaction between protein and nanoparticles is proving to be of fundamental interest for bio-functionalization of materials. The interaction of glycine (Gly) amino acid with Au32 fullerene was frst investigated with B3LYP-D3/TZVP model. Several forms of glycine were selected to better understand the trends in binding nature of glycine interacting with the nanocage. We have evaluated various stable confgurations of the Gly/Au32 complexes and the calculated adsorption energies and AIM analysis indicate that non-Gly, z-Gly and also tripeptide glycine can form stable bindings with Au32 at aqueous solution via their amino nitrogen (N) and/or carbonyl/carboxyl oxygen (O) active sites. Furthermore, cysteine, tyrosine, histidine and phenylalanine amino acids bound also strongly to the Au32 nanocage. Electronic structures and quantum molecular descriptors calculations also demonstrate the signifcant changes in the electronic properties of the nanocage due to the attachment of selected amino acids. DFT based MD simulation for the most stable complex demonstrate that Gly/Au32 complex is quite stable at ambient condition. Our frst-principles fndings ofer fundamental insights into the functionalization of Au32 nanocage and envisage its applicability as novel carrier of the drugs. Drug delivery has gained a lot of attention as it can minimize the side efects of various drugs.
    [Show full text]
  • Internal Structure of Polyelectrolyte Multilayers on Nanometer Scale
    INTERNAL STRUCTURE OF POLYELECTROLYTE MULTILAYERS ON NANOMETER SCALE Inauguraldissertation zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften der Mathematisch-Naturwissenschaftlichen Fakult¨at der Ernst-Moritz-Arndt-Universit¨atGreifswald vorgelegt von Oxana Ivanova geboren am 06. April 1980 in Sankt-Petersburg (Russland) - Greifswald, 2010 - Dekan: Prof. Dr. Dr. Klaus Fesser 1. Gutachter: Prof. Dr. Christiane A. Helm 2. Gutachter: Prof. Dr. Monika Sch¨onhoff Tag der Promotion: 15. Oktober 2010 Ich m¨ochte mich ganz herzlich bei allen Mitarbeitern des Instituts f¨urPhysik f¨urzahllose fachverwandte sowie fachfremde Unterst¨utzungbedanken. Contents I Introduction to the Field of Research 7 1 Introduction 9 1.1 Polyelectrolytes and their Properties . 9 1.2 Layer-by-Layer Assembly of Polyelectrolytes . 10 1.3 Polyelectrolyte Multilayers . 13 1.4 Objectives . 15 2 Physical Background 17 2.1 Electrostatic and Secondary Interactions . 17 2.1.1 Electrostatic Interactions: Electric Double Layer . 18 2.1.2 Effect of Salt on Formation of PEMs . 21 2.1.3 Classification and Range of Intermolecular Forces . 22 2.1.4 Temperature Effect: Hydrophobic Interactions . 23 II Materials and Methods 25 3 Materials and Sample Preparation 27 3.1 Chemicals . 27 3.2 Fabrication of Multilayered Nanofilms . 29 4 Characterization Methods 33 4.1 X-ray and Neutron Reflectivity . 33 4.1.1 Basic Principles of X{ray and Neutron Reflection . 35 4.1.2 Reflection from Ideally Smooth & Rough Interfaces . 37 4.1.3 Refractivity Set{up . 41 4.2 UV-Vis Absorption Spectroscopy . 43 4.2.1 Interaction of Light with Matter . 43 4.2.2 Beer-Lambert Law .
    [Show full text]
  • Size and Zeta Potential of Colloidal Gold Particles
    Size and Zeta Potential of Colloidal Gold Particles Mark Bumiller [email protected] © 2012 HORIBA, Ltd. All rights reserved. Colloid Definition Two phases: •Dispersed phase (particles) •Continuous phase (dispersion medium, solvent) May be solid, liquid, or gaseous Size range 1 nm – 1 micron High surface area creates unique properties (suspension) © 2012 HORIBA, Ltd. All rights reserved. Nanoparticle Definition Nanoparticle: size below 100 nm SSA = 6/D ultrasound 50 nm D from SEM ~50 nm Used ultrasound to disperse D from SSA ~60-70 nm to primary particles or use D from DLS ~250 nm weak acid to break bonds So: is this a nanoparticle? D from DLS ~50 nm © 2012 HORIBA, Ltd. All rights reserved. SZ-100: Nanoparticle Analyzer Size: .3 nm - 8 µm 90° and 173° Zeta potential: -200 - +200 mV Patented carbon coated electrodes Molecular weight: 1x103 - 2x107 g/mol Optional titrator •Nanoparticles •Colloids •Proteins •Emulsions •Disperison stability © 2012 HORIBA, Ltd. All rights reserved. Dynamic Light Scattering Particles in suspension undergo Brownian motion due to solvent molecule bombardment in random thermal motion. ~ 1 nm to 1 µm Particle moves due to interaction with liquid molecules Small – faster Large - slower © 2012 HORIBA, Ltd. All rights reserved. SZ-100 Optics 90° for size and MW, A2 Backscatter (173°) (High conc.) Particles Laser PD Attenuator 532nm, 10mW For T% Particles moving due to Brownian motion Zeta potential Attenuator Modulator © 2012 HORIBA, Ltd. All rights reserved. SZ100 Measurement Principle 1 lngq,r lim 0 ts R n(i) Relaxation time n(1)=2 n(3)=1 n(5)=2 2 n(2)=1 n(4)=3 t t 6D Particle’s moving distance <n(i)n(i+j)> Diffusion constant j 0 4 5 1 k T 1 2 3 D B <n2(i)> 2 Autocorrelation Function q R 6a g(q、r) Relaxation time <n(i)>2 Particle radius j 0 1 2 3 4 5 q: Scattering vector η: Viscosity 0 t 2t 3t 4t 5t k : Boltzmann constant s s s s s τ B © 2012 HORIBA, Ltd.
    [Show full text]
  • Characterization and Functionalization of Iron-Oxide Nanoparticles for Use As Potential Agents for Cancer Thermotherapy at the U
    Characterization and Functionalization of Iron-Oxide Nanoparticles for Use as Potential Agents for Cancer Thermotherapy By Nora O’Reilly A dissertation submitted in partial fulfillment of the requirement for the degree of Doctor of Philosophy (Animal Science) At the University of Wisconsin-Madison 2013 Date of final oral examination: April 18th, 2013 The dissertation is approved by the following members of the Final Oral Committee: Professor Ralph Albrecht, Animal Science, Pediatrics, Pharmaceutical Sciences Professor Mark Cook, Animal Science Professor Amin Fadl, Animal Science Professor Manish Patankar, Obstetrics and Gynecology Professor Chris Brace, Radiology, Biomedical Engineering i Abstract This thesis presents experimental studies of iron oxide nanoparticle synthesis, functionalization, and intracellular hyperthermal effects on murine macrophages as a model in vitro system. Colloidal suspensions of magnetic nanoparticles (MNPs) are of particular interest in Magnetic Fluid Hyperthermia (MFH). Iron oxide nanoparticles (IONPs) have garnered great interest as economical, biocompatible hyperthermia agents due to their superparamagnetic activity. Here we seek to optimize the synthetic reproducibility and in vitro utilization of IONPs for application in MFH. We compared aqueous synthetic protocols and various protective coating techniques using various analytical techniques and in vitro assays to assess the biocompatibility and feasibility of the various preparations of nanoparticles. Using a co-precipitation of iron salts methodology,
    [Show full text]
  • Gold Nanoparticles and Quantum Dots: Their Optical Interaction and Application in a Hydrogel Modified Lateral Flow Sensing Device Julie A
    University of Connecticut OpenCommons@UConn Doctoral Dissertations University of Connecticut Graduate School 6-8-2017 Gold Nanoparticles and Quantum Dots: Their Optical Interaction and Application in A Hydrogel Modified Lateral Flow Sensing Device Julie A. Jenkins University of Connecticut - Storrs, [email protected] Follow this and additional works at: https://opencommons.uconn.edu/dissertations Recommended Citation Jenkins, Julie A., "Gold Nanoparticles and Quantum Dots: Their Optical Interaction and Application in A Hydrogel Modified Lateral Flow Sensing Device" (2017). Doctoral Dissertations. 1521. https://opencommons.uconn.edu/dissertations/1521 Gold Nanoparticles and Quantum Dots: Their Optical Interaction and Application in A Hydrogel Modified Lateral Flow Sensing Device Julie Ann Jenkins, Ph.D. University of Connecticut, 2017 The goal of this dissertation was to study the optical properties of gold nanoparticles (Au NP) and quantum dots (QD) and to use their unique properties in sensing applications. The first part of this dissertation focuses on studying the dipole coupling in a gold nanoparticle random array. A blue shift and narrowing of the extinction peak, when compared to the single particle and solution spectra, was observed when 120 nm Au NPs were randomly immobilized on a glass substrate. This was determined to be due to the long-range dipole coupling of the Au NPs in the array. The motivation behind the second project was to study the temperature dependent change in decay kinetics of aqueous phase quantum dots when in close proximity to 120 nm Au NP, using α-carboxy-ω-Thiol terminated Poly(N-isopropyl acrylamide) (PNIPAM) as a spacer. The structure of PNIPAM will expand or collapse based with a change in temperature, thus varying the interparticle distance between the QD and the Au NP.
    [Show full text]
  • THE OPTIMIZATION of GOLD COATED IRON NANOPARTICLE SYNTHESIS METHODS by Mark Riggs, B.S., B.S. a Thesis Submitted to the Gradua
    THE OPTIMIZATION OF GOLD COATED IRON NANOPARTICLE SYNTHESIS METHODS by Mark Riggs, B.S., B.S. A thesis submitted to the Graduate Council of Texas State University in partial fulfillment of the requirements for the degree of Master of Science with a Major in Chemistry August 2014 Committee Members: Gary Beall Shannon Weigum Clois Powell COPYRIGHT by Mark Riggs 2014 FAIR USE AND AUTHOR’S PERMISSION STATEMENT Fair Use This work is protected by the Copyright Laws of the United States (Public Law 94-553, section 107). Consistent with fair use as defined in the Copyright Laws, brief quotations from this material are allowed with proper acknowledgment. Use of this material for financial gain without the author’s express written permission is not allowed. Duplication Permission As the copyright holder of this work I, Mark Riggs, authorize duplication of this work, in whole or in part, for educational or scholarly purposes only. DEDICATION I dedicate this to my wife, Melissa. Her constant support and encouragement were nothing short of heroic. Careful and delicate allocation of my focus became ever- increasing in importance throughout the progression of this research, primarily due to the birth of my beautiful daughter, Olivia Marie, on February 4th of 2014. My daughter’s arrival impacted my perception in ways I couldn’t have fully understood prior to that wonderful moment. I will be forever indebted to Melissa for showing me how blessed I am, enabling me to live a better life than I could have conceived, and providing never- ending assistance with caring for our daughter.
    [Show full text]
  • Functionalization of Gold Nanoparticles by Inorganic Entities
    nanomaterials Review Functionalization of Gold Nanoparticles by Inorganic Entities Frédéric Dumur 1,* , Eddy Dumas 2 and Cédric R. Mayer 3,4,* 1 Aix Marseille Univ, CNRS, ICR, UMR 7273, F-13397 Marseille, France 2 Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles Saint-Quentin-en-Yvelines, F-78035 Versailles, France; [email protected] 3 Laboratoire LuMin, FRE CNRS 2036, CNRS, Université Paris-Sud, ENS Paris-Saclay, Université Paris-Saclay, F-91405 Orsay CEDEX, France 4 Département de Chimie, UFR des Sciences, Université de Versailles Saint-Quentin-en-Yvelines, F-78035 Versailles, France * Correspondence: [email protected] (F.D.); [email protected] (C.R.M.); Tel.: +33-0491289059 (F.D.) Received: 25 February 2020; Accepted: 13 March 2020; Published: 18 March 2020 Abstract: The great affinity of gold surface for numerous electron-donating groups has largely contributed to the rapid development of functionalized gold nanoparticles (Au-NPs). In the last years, a new subclass of nanocomposite has emerged, based on the association of inorganic molecular entities (IME) with Au-NPs. This highly extended and diversified subclass was promoted by the synergy between the intrinsic properties of the shell and the gold core. This review—divided into four main parts—focuses on an introductory section of the basic notions related to the stabilization of gold nanoparticles and defines in a second part the key role played by the functionalizing agent. Then, we present a wide range of inorganic molecular entities used to prepare these nanocomposites (NCs). In particular, we focus on four different types of inorganic systems, their topologies, and their current applications.
    [Show full text]
  • Functionalization of Gold Nanoparticles by Inorganic Entities Frédéric Dumur, Eddy Dumas, Cédric Mayer
    Functionalization of Gold Nanoparticles by Inorganic Entities Frédéric Dumur, Eddy Dumas, Cédric Mayer To cite this version: Frédéric Dumur, Eddy Dumas, Cédric Mayer. Functionalization of Gold Nanoparticles by Inorganic Entities. Nanomaterials, MDPI, 2020, 10 (3), pp.548. 10.3390/nano10030548. hal-02542642 HAL Id: hal-02542642 https://hal.archives-ouvertes.fr/hal-02542642 Submitted on 1 Jul 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Review Functionalization of Gold Nanoparticles by Inorganic Entities Frédéric Dumur 1,*, Eddy Dumas 2 and Cédric R. Mayer 3,4 1 Aix Marseille Univ, CNRS, ICR, UMR 7273, F-13397 Marseille, France 2 Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles Saint-Quentin-en-Yvelines, F-78035 Versailles, France 3 Laboratoire LuMin, FRE CNRS 2036, CNRS, Université Paris-Sud, ENS Paris-Saclay, Université Paris- Saclay, F-91405 Orsay CEDEX, France 4 Département de Chimie, UFR des Sciences, Université de Versailles Saint-Quentin-en-Yvelines, F-78035 Versailles, France * Correspondence: [email protected]; Tel.: +33-0491289059 Received: 25 February 2020; Accepted: 13 March 2020; Published: 18 March 2020 Abstract: The great affinity of gold surface for numerous electron-donating groups has largely contributed to the rapid development of functionalized gold nanoparticles (Au-NPs).
    [Show full text]
  • Gold, Silver and Platinum Nanoparticles: from New Synthetic
    Adrián Fernández Lodeiro Gold, Silver and Platinum Nanoparticles: From New Synthetic Routes to Sensing, Catalysis and Bio-Applications Dissertação para a obtenção do Grau de Doutor em Química Sustentável Orientador Doutor José Luís Capelo Martínez Professor Associado com Agregação Faculdade de Ciências e Tecnologia (FCT) Universidade Nova de Lisboa (UNL), Portugal Co-Orientadores Doutora Julia Lorenzo Rivera Visiting Professor, Universitat Autònoma de Barcelona, UAB, Spain Doutor Hugo Miguel Baptista Carreira dos Santos Investigador Auxiliar, FCT Investigator Programme, FCT, UNL, Portugal Júri Presidente Prof. Doutor Manuel Luís De Magalhães Nunes Da Ponte Vogais Prof. Doutor Gilberto Paulo Peixoto Igrejas Prof. Doutor José Luís Capelo Martínez Prof. Doutor Jorge Pérez Juste Doutora Elisabete De Jesus Oliveira Marques March - 2019 Adrián Fernández Lodeiro Gold, Silver and Platinum Nanoparticles: From New Synthetic Routes to Sensing, Catalysis and Bio-Applications Dissertação para a obtenção do Grau de Doutor em Química Sustentável (Sustainable Chemistry) Orientador Doutor José Luís Capelo Martínez Professor Associado com Agregação Faculdade de Ciências e Tecnologia (FCT) Universidade Nova de Lisboa (UNL), Portugal Co-Orientadores Doutora Julia Lorenzo Rivera Visiting Professor, Universitat Autònoma de Barcelona, UAB, Spain Doutor Hugo Miguel Baptista Carreira dos Santos Investigador Auxiliar, FCT Investigator Programme, FCT, UNL, Portugal Júri Presidente Prof. Doutor Manuel Luís De Magalhães Nunes Da Ponte Vogais Prof. Doutor Gilberto
    [Show full text]
  • Down Strategy Towards Monodisperse Colloidal Lead Sulphide Quantum Dots
    ARTICLE Received 16 Oct 2012 | Accepted 21 Feb 2013 | Published 16 Apr 2013 DOI: 10.1038/ncomms2637 A top–down strategy towards monodisperse colloidal lead sulphide quantum dots Jing Yang1, Tao Ling1, Wen-Tian Wu1, Hui Liu1, Min-Rui Gao1, Chen Ling1, Lan Li2 & Xi-Wen Du1 Monodisperse colloidal quantum dots with size dispersions o10% are of great importance in realizing functionality manipulation, as well as building advanced devices, and have been normally synthesized via ‘bottom–up’ colloidal chemistry. Here we report a facile and environmentally friendly ‘top–down’ strategy towards highly crystalline monodisperse colloidal PbS quantum dots with controllable sizes and narrow dispersions 5.5%oso9.1%, based on laser irradiation of a suspension of polydisperse PbS nanocrystals with larger sizes. The colloidal quantum dots demonstrate size-tunable near-infrared photoluminescence, and self-assemble into well-ordered two-dimensional or three-dimensional superlattices due to the small degree of polydispersity and surface capping of 1-dodecanethiol, not only serving as a surfactant but also a sulphur source. The acquisition of monodisperse colloidal PbS quantum dots is ascribed to both the quantum-confinement effect of quantum dots and the size-selective-vaporization effect of the millisecond pulse laser with monochromaticity and low intensity. 1 Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072, People’s Republic of China. 2 Key Laboratory of Display Materials and Photoelectric Devices, Ministry of Education, Institute of Material Physics, and Tianjin Key Laboratory for Photoelectric Materials and Devices, Tianjin University of Technology, Tianjin 300384, People’s Republic of China.
    [Show full text]
  • Fluorescent Fullerene Nanoparticle-Based Lateral Flow Immunochromatographic Assay for Rapid Quantitative Detection of C-Reactive
    Park et al. Nano Convergence (2019) 6:35 https://doi.org/10.1186/s40580-019-0207-0 RESEARCH Open Access Fluorescent fullerene nanoparticle-based lateral fow immunochromatographic assay for rapid quantitative detection of C-reactive protein Kyung Mi Park1, Da Jung Chung1, Mijin Choi1, Taejoon Kang2,3* and Jinyoung Jeong3,4* Abstract A fuorescent fullerene nanoparticle (NP)-based lateral fow immunochromatographic assay (LFIA) was developed for the rapid and quantitative detection of C-reactive protein (CRP) in serum. The polyclonal CRP-antibody-conjugated fullerene NPs were simply prepared by 1-ethyl-3-(3-dimethyllaminopropyl)-carbodiimide hydrochloride coupling after carboxylation of fuorescent fullerene NPs. By applying the CRP-antibody-conjugated fullerene NPs to a lateral fow test strip, quantitative analysis of CRP in serum was possible at a concentration range of 0.1–10 ng/ml within 15 min. We anticipate that this novel fuorescent fullerene NP-based LFIA can be useful for the rapid and accurate sensing of biological and chemical species, contributing to the disease diagnosis and prognosis, environmental monitoring, and food safety. Keywords: Fullerene, Nanoparticle, C-reactive protein, Lateral fow immunochromatographic assay, Fluorescence 1 Introduction sensitive and quantitative analyses of molecules even at Te lateral fow immunochromatographic assay (LFIA) low analyte concentrations, challenges remain in terms is a common technique for the detection of such diverse of material preparation, functionalization of the materi- analytes as hormones, disease-related biomarkers, and als for efcient conjugation of the target molecules, and toxins in the clinical, environmental, and food industry optimization of sensing conditions on a lateral fow assay. felds, because of its simplicity and rapidity [1–8].
    [Show full text]
  • Fabrication of Nanostructures by Hydroxylamine Seeding of Gold Nanoparticle Templates
    Langmuir 2001, 17, 1713-1718 1713 Fabrication of Nanostructures by Hydroxylamine Seeding of Gold Nanoparticle Templates Sheffer Meltzer, Roland Resch, Bruce E. Koel,* Mark E. Thompson, Anupam Madhukar, Aristides A. G. Requicha, and Peter Will Laboratory for Molecular Robotics, University of Southern California, 37th Street, University Park, Los Angeles, California 90089-0482 Received August 14, 2000. In Final Form: December 18, 2000 Hydroxylamine-seeding of colloidal gold particles has been used to fabricate gold nanostructures on a SiO2 substrate. Gold nanoparticles (15 nm diameter) were randomly deposited on a SiO2 surface that had been modified with aminopropyltrimethoxysilane (APTS). The nanoparticles were then manipulated using a scanning force microscope (SFM) tip to produce 1-D templates for gold deposition. We demonstrate the utility of this approach by fabricating a gold nanowire by using 13 nanoparticles as a template. The junction between joined (coated) particles was examined by mechanical manipulation, and homogeneous deposition was shown to form stable structures. This approach was also used to fabricate nanostructures in a small gap between two gold electrodes. Particles were pushed into the gap, and then gold deposition was used to “connect” the particles and electrodes. Although the particular structure tested was not electrically connected to the electrode, we suggest that this approach will be useful in tackling the difficult problems associated with electrically connecting nano- to microscale structures. Introduction Another approach for nanostructuring is the use of well- defined structures as templates. It is possible to use The fabrication of nanostructures is being pursued with inherent surface structures, e.g., atomic steps, recon- increasing interest and activity in chemistry, physics, 1 2 struction sites, and grain boundaries, as templates.
    [Show full text]