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Conducting Polymer Nanowires for Multi-Analyte Chemiresistive Sensing Edward Song Louisiana State University and Agricultural and Mechanical College

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Conducting Polymer Nanowires for Multi-Analyte Chemiresistive Sensing Edward Song Louisiana State University and Agricultural and Mechanical College Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2014 Conducting polymer nanowires for multi-analyte chemiresistive sensing Edward Song Louisiana State University and Agricultural and Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Electrical and Computer Engineering Commons Recommended Citation Song, Edward, "Conducting polymer nanowires for multi-analyte chemiresistive sensing" (2014). LSU Doctoral Dissertations. 3390. https://digitalcommons.lsu.edu/gradschool_dissertations/3390 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. CONDUCTING POLYMER NANOWIRES FOR MULTI-ANALYTE CHEMIRESISTIVE SENSING A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The School of Electrical Engineering and Computer Science by Edward Song B.Sc., Queen’s University, Canada, 2004 M.Sc., University of Alberta, Canada, 2007 August 2014 Acknowledgements First, I would like to express my deep appreciation to my advisor Dr. Jin-Woo Choi for his guidance and suggestions throughout the course of this research work. I am very grateful to have him as a mentor, and his professionalism in teaching and research is very much appreciated. I would also like to thank my committee members Dr. Sunggook Park, Dr. Robin McCarley, Dr. Georgios Veronis, Dr. Kidong Park, and Dr. Peter Kelle for taking their time and effort to review my work and to provide positive feedback and suggestions that have greatly improved the quality of my work. I would like to extend my appreciation to the cleanroom staff members at the Center for Advanced Materials and Devices for their assistance in microfabrication and SEM imaging. I wish to give my special thanks to my friends and colleagues: Chao-Xuan Liu, Jeonghwan Kim, Kyung-Nam Kang, Junseo Choi, and the members of the BioMEMS and Bioelectronics Lab for many helpful discussions about the research work and for making my time at LSU more memorable. Finally, I am grateful to have such a wonderful family: my grandmother, mom, dad, my brother and sister-in-law, and my fiancé Hana for their endless prayer and support. I would not be where I am today without them, and for that, I dedicate this thesis to my family. ii Table of Contents Acknowledgements ......................................................................................................................... ii List of Tables ................................................................................................................................. vi List of Figures ............................................................................................................................... vii Abstract ......................................................................................................................................... xii 1. Introduction ............................................................................................................................... 1 1.1. Motivation ........................................................................................................................... 1 1.2. Objectives ........................................................................................................................... 4 1.2.1. Synthesis and Characterization of Polyaniline Nanowires ....................................... 4 1.2.2. Self-Calibration of the Polyaniline Nanowire-Based Chemiresistive Sensor........... 5 1.2.3. Nanoparticle-Functionalized Polyaniline Nanowires ............................................... 5 1.2.4. Development of a Sensor Array for Multi-Analyte Detection Capability ................ 6 1.3. Dissertation Outline ............................................................................................................ 6 2. Background ............................................................................................................................... 8 2.1. Introduction ......................................................................................................................... 8 2.2. Overview of Polyaniline Nanowires ................................................................................... 8 2.2.1. Chemical Structure and Electrochemical Properties ................................................. 9 2.2.2. Electronic Conduction ............................................................................................ 13 2.2.3. Synthesis Methods .................................................................................................. 15 2.2.4. Chemical Synthesis vs. Electrochemical Synthesis ................................................ 20 2.3. Polyaniline Nanowire-Based Chemiresistive Sensors ...................................................... 21 2.3.1. Gas Sensors ............................................................................................................. 21 2.3.2. Biosensors ............................................................................................................... 22 2.4. Current Limitations of Polyaniline-Based Sensors ........................................................... 23 2.5. Conclusions ....................................................................................................................... 27 3. Synthesis and Characterization of a Polyaniline Nanowires .................................................. 28 3.1. Introduction ....................................................................................................................... 28 3.2. Electrochemical Synthesis of Polyaniline Nanowires ...................................................... 28 3.2.1. Electrode Design ..................................................................................................... 29 3.2.2. Electrochemical Setup ............................................................................................ 32 3.2.3. Polymer Synthesis Process ..................................................................................... 33 3.3. Morphology Characterization of Polyaniline Nanowires ................................................. 35 3.4. Chemiresistive pH Sensor ................................................................................................. 37 3.4.1. Conduction Current vs. Bias Potential Characteristics ........................................... 37 3.4.2. Hysteresis Analysis ................................................................................................. 39 3.4.3. Repeatability Analysis ............................................................................................ 41 3.4.4. Degradation ............................................................................................................. 43 3.4.5. Polystyrene Sulfonate-Doped Polyaniline .............................................................. 45 3.5. Conclusions ....................................................................................................................... 45 iii 4. Self-Calibration of a Polyaniline Nanowire-Based Chemiresistive pH Sensor ..................... 47 4.1. Introduction ....................................................................................................................... 47 4.2. Working Principle ............................................................................................................. 47 4.3. Peak Current vs. Potential Sweep Characterization .......................................................... 50 4.4. pH Detection Utilizing the Ratio of Peak Current Reduction ........................................... 51 4.5. pH Detection with IC at VB = +0.5 V ................................................................................ 53 4.6. Repeatability Test ............................................................................................................. 56 4.7. Conclusions ....................................................................................................................... 57 5. A Selective Sensor Based on Polyaniline Nanowires with Catalysts ..................................... 59 5.1. Introduction ....................................................................................................................... 59 5.2. Basic Principle of a Catalyst-Assisted Chemiresistive Sensor ......................................... 59 5.3. Experimental Methods ...................................................................................................... 62 5.3.1. Preparation of Catalyst Nanoparticles .................................................................... 62 5.3.2. Background pH Environment ................................................................................. 63 5.4. Selecting Target Chemical Species ................................................................................... 64 5.5. Selective Detection of Hydrogen Peroxide using Silver Nanoparticles as Catalysts ....... 67 5.5.1. Motivation ............................................................................................................... 68 5.5.2. Working Concept ...................................................................................................
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