INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
Chemiresistive Vapor and Gas Sensing with Films of Chemically-modified Nanoparticles
Autor/es:
IBAÑEZ, FRANCISCO J. AND ZAMBORINI, FRANCIS P.
Revista:
ANALYTICA CHIMICA ACTA
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Año: 2009
ISSN:
0003-2670
Resumen:
This review describes the use of chemically-modified pure and alloy metal nanoparticles for chemiresistive sensing applications.  Chemiresistors are materials that change their resistance in the presence of a particular analyte of interest.  Chemically-modified metal nanoparticles consist of a pure or alloy metallic core that has some type of chemical coating, which could be an organic monolayer, polymer, surfactant, biomolecules, inorganic material, or organometallic molecules.  For years, researchers have studied the electronic properties of chemically-modified metal nanoparticles once they are organized into one-dimensional (1D), two-dimensional (2D), or three-dimensional (3D) assemblies or even as single individual nanoparticles.  Once they are assembled onto a device where their electronic properties can be measured, they become well-suited for chemiresistive sensing applications because the metallic core provides a conductive path and the nanoparticle coating provides a means for controlling the interaction with an analyte of interest, which then alters the conductivity of the material.  Much of this review will focus on the use of metal monolayer-protected clusters (MPCs) for chemiresistive sensing applications.  This particular class of nanoparticles consists of a pure or alloy metallic core surrounded by a self-assembled monolayer coating, usually an organomercaptan or amine-based ligand.  The versatile and well-understood synthesis of MPCs has allowed researchers to tailor the size and composition of the metallic core and coating for chemiresistive sensing of a wide variety of gas and liquid phase analytes.  This review will also describe chemiresistive sensing applications of other types of metal nanoparticles synthesized with different coatings (or stabilizers), such as ions, polymers, surfactants, and biomolecules.  Chemiresistive sensing can be performed with these materials assembled as large scale or micro/nano-patterend films or as individual particles.  The nanoparticles may be chemically-linked or assembled with weaker intermolecular forces.  Here we will review the different strategies used to incorporate chemically-modified nanoparticles into chemiresistive sensing devices.  This review describes the different types of metals and alloys used, types of coatings, methods of assembly, types of analytes (vapors, gases, liquid phase, biological), and other various factors, such as particle size, stability, conditioning steps, and practical considerations.  This review also includes a summary and future directions of the field.