Special Issue "Metal-oxide Based Nanosensors"

Guest Editor
Prof. Dr. Laszlo B. Kish
Professor, Texas A&M University, Department of Electrical Engineering, College Station, TX 77843-3128, USA
Website: http://www.ece.tamu.edu/People/bios/bkish.html
E-Mail:
Interests: noise and fluctuations; noise-based logic and computing, including superior-to-quantum and brain models; unconditionally secure computers, hardware, memories and algorithms; unconditionally secure non-quantum communication and networks; stealth communication, zero-quantum quantum communication, zero power classical communication; vibration-induced conductance fluctuation (VICOF) analysis of soils; fluctuation-enhanced chemical sensing, fluctuation-enhanced biological sensing

Guest Editor
Dr. Gabor Schmera
Space and Naval Warfare System Center, Signal Exploitation & Information Management, San Diego, CA 92152-5001, USA
E-Mail:

Going to the nanoscales changes the characteristic material properties, and characteristic lengths/timescales of dominant interactions. In metal-oxide based nanosensors, these effects have resulted in higher sensing-information-channel-capacity that includes increased sensitivity, higher selectivity, and increased speed. Room temperature applications allow low-power devices.

In this special issue, the metal-oxide based sensor structures of interest include: nanoparticles, nanolayers, nanowires, thin films with nanostructures, functionalization, nanoscale coating and phases, nanocomposites, carbon nanotube - oxide systems, catalytic metal - oxide junctions, etc. Among others, the following sub-topics are of interest:

• Fabrication, design, methodology
• Characterization, physical, chemical and sensing properties
• Transduction mechanism: resistance, field-effect, thermoelectric, photoelectric, fluctuation-statistics, etc.
• Reproducibility, sensitivity, selectivity
• Recognition principle and sensor signal processing: information-enhancement, linear and nonlinear filtering, pattern recognition, fluctuation-enhanced sensing, etc.
• Applications: environmental, medical, food, defense, etc.
• Agent-specific sensors and electronic noses
• Sensing at room temperatures and other ways of reducing power requirements

Submission

• nanoparticles
• nanolayers
• nanowires
• thin films with nanostructures
• functionalization
• nanoscale coating and phases
• nanocomposites
• carbon nanotube - oxide systems
• catalytic metal - oxide junctions

Title: Multifunctional Metal-Oxide Based Core-Shell Nanostructures for Chemosensing and Biosensing
Author: Tewodros (Teddy) Asefa, Assistant Professor of Chemistry and Biochemistry, Department of Chemistry, Syracuse University, Syracuse, NY 13244, USA; E-Mail: tasefa@syr.edu; Website: http://www-che.syr.edu/faculty/asefa.html
Abstract: Inorganic nanomaterials with controllable sizes and shapes exhibit a wide range of unique physical, chemical, electrical, surface, and optical properties. Metal oxide nanomaterials that are decorated with different types of metal nanoparticles show strong shape- and size-dependent optical absorptions in the visible and near-IR region of the electromagnetic spectrum. In addition, the placement of different types of organic and bioactive functional groups onto these nanomaterials allows the selective binding and detection of specific pollutants or biological agents. By exploiting the unique optical and surface properties of the metal nanoparticles and by using the properties of the organic and biological functional groups, new types of sensitive and efficient sensors and biosensors for the detection of chemical compounds and common pathogens can be fabricated. These multifunctional nanosensors utilize interactions such as antibody-antigen recognition, electrochemical properties of electroactive species and optical properties of the metal nanoparticles for efficient and selective detection various analytes. The surface of the nanomaterial or the sensors can be tuned in such a way that it can anchor large numbers of functional groups or tunable metal nanoparticles to enhance their sensitivity and detection limit. In this review, we describe efforts from our group and others on the development of synthetic strategies to multifunctional core-shell nanostructure based sensors on metal oxide platforms for efficient detection of chemical compounds as well as biological agents under a variety of environmental conditions. The core metal-oxide structure in these mutifunctional core-shell nanosensors include silica nanospheres, corrugated silica nanospheres, shaped metal oxide nanoparticles, and mesoporous materials having tunable surface properties, high surface areas and supported metal nanoparticles and organic species.

Title: Nano-crystalline metal oxide for development of solid-state gas sensors
Author: Ghim Wei HO
Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive, 117576, Singapore
Abstract: There is always a great interest in maximizing the sensitivity of sensing devices made of nano-crystalline metal oxides for applications such as security and process control in environmental, domestic, public and automotive industry. Metal oxides are often the choice for conductometric gas sensing due to their thermal and environmental stability as well as good response reversibility. Due to the fact that sensing with these materials relies on interactions with the surface, one strategy to enhance the sensitivity is to increase the surface area or active sites by decreasing their physical dimensions. Thus, nanosized metal oxides such as nanoparticles, nanospheres, nanotubes, nanobelts and nanowires are routinely synthesized for development of solid-state gas sensors with improved sensing properties. It is apparent that the full potential for gas sensing application of the prepared nanostructures can only be realized when they are synthesized in large quantities with reproducible geometries, structures, crystallinity and compositions. The key factors to consider for gas sensing applications include the adsorption ability, electronic, physical and chemical properties, catalytic activity, thermodynamic stability, crystallographic structure, reliability and compatibility with materials and technologies to be used in gas sensors fabrications. In this review paper, we will focus on chemiresistors gas sensors, and on catalytic type gas sensors which operate base on surface interactions of nano-crystalline metal oxide. These sensors have the characteristics of high sensitivity, short response time, low cost, and good compatibility for design of portable electronic nose.

Type of Paper: Review
Title: Effect of Nanostructuring on Metal Oxide Performance as Gas Sensors: A Review of Theoretical Modelling Studies
Authors: Michelle J. S. Spencer and Irene Yarovsky
Affiliation: Applied Physics, School of Applied Sciences, RMIT University, Melbourne, VIC, 3001, Australia; E-Mail: irene.yarovsky@rmit.edu.au (I.Y.)
Abstract: Gas sensor devices have traditionally comprised thin films of metal oxides, with tin oxide, zinc oxide and indium oxide being some of the most common materials employed. With the recent discovery of novel metal oxide nanostructures, however, sensors comprising nanoarrays or single nanostructures have shown improved performance over the thin films. The improved response has been primarily attributed to the presence of highly single crystalline surfaces as well as large surface area due to nanostructuring. Theoretical calculations using Density Functional Theory (DFT) and ab-initio approaches have been useful in elucidating the effects of nanoscale and electronic structure on reaction mechanism, binding strength, charge transfer as well as other properties of the gas-sensor interaction. In this paper we review the theoretical studies of the interactions of different gases with "traditional" and nanostructured metal oxides surfaces for sensing purposes.

Type of Paper: Review
Title: Metal Oxide Sensors for Electronic Noses and Their Application to Food Analysis
Author: Amalia Z. Berna
Affiliation: CSIRO Entomology and CSIRO Food Futures Flagship GPO Box 1700, Canberra ACT 2601, Australia; E-Mail: amalia.berna@csiro.au
Abstract: Electronic noses (Enose) systems may use various types of electronic gas sensors that have partial specificity. This review focuses on commercial and non-commercial Enoses that use metal oxide semiconductors, specifically tin oxide, SnO₂, doped with small amounts of catalytic metal such as palladium or platinum. The review covers quality control applications to food and beverages, including determination of freshness and identification of contaminants or adulteration. Applications of Enoses to a wide range of foods and beverages are considered including: meat, fish, grains, alcoholic drinks including wine, non-alcoholic drinks including tea and coffee, fruits, dairy products, olive oil, nuts, eggs and bread.

Type of Paper: Review
Title: A Comprehensive Review on Glucose Biosensor Based on Nanostructured Metal-Oxide
Authors: Md. Mahbubur Rahman ¹, A. J. Saleh Ahammad ¹, Joon-Hyung Jin ² and Jae-Joon Lee ^1,3
Affiliations: ¹ Department of Advanced Technology Fusion, Konkuk University, Seoul 143-701, Korea
² KFnSC Center, Konkuk University, Seoul 143-701, Korea
³ Department of Applied Chemistry, Konkuk University, Chungju 380-701, Korea; E-Mail: jjlee@kku.ac.kr (J.J.L.)
Abstract: The promising nanotechnology has opened new exhilarating opportunities to explore glucose biosensing application of the freshly prepared nanostructured materials. Nanostructured metal-oxide has been extensively explored to develop a biosensor with high sensitivity, fast response time, and stability for the determination of glucose by electrochemical oxidation. This article concentrates the most attention on the development of different nanostructured metal-oxides ( such as ZnO, Cu(I)/(II) oxides, TiO₂, CeO₂, MnO₂ , SnO₂, SiO₂, ZrO₂, and other metal-oxides) based glucose biosensor. Additionally, we devote our attention on to the operating principal (i.e potentiometric, amperometric, impedimetric etc.) of these nanostructured metal-oxide based glucose sensor. Finally, this review concludes the personal prospective, outlook, and future application of these nanoscaled sensors.