title: A Review: Origins of the Dielectric Properties of Proteins and Potential Development as Bio-Sensors.
abstract: Polymers can be classified as synthetic polymers and natural polymers, and are often characterized by their most typical functions namely their high mechanical resistivity, electrical conductivity and dielectric properties. This bibliography report consists in: (i) Defining the origins of the dielectric properties of natural polymers by reviewing proteins. Despite their complex molecular chains, proteins present several points of interest, particularly, their charge content conferring their electrical and dielectric properties; (ii) Identifying factors influencing the dielectric properties of protein films. The effects of vapors and gases such as water vapor, oxygen, carbon dioxide, ammonia and ethanol on the dielectric properties are put forward; (iii) Finally, potential development of protein films as bio-sensors coated on electronic devices for detection of environmental changes particularly humidity or carbon dioxide content in relation with dielectric properties variations are discussed. As the study of the dielectric properties implies imposing an electric field to the material, it was necessary to evaluate the impact of frequency on the polymers and subsequently on their structure. Characterization techniques, on the one hand dielectric spectroscopy devoted for the determination of the glass transition temperature among others, and on the other hand other techniques such as infra-red spectroscopy for structure characterization as a function of moisture content for instance are also introduced.
authors.affiliation: Joint Research Unit Agropolymers Engineering and Emerging Technologies, UMR 1208 INRA/SupAgroM/UMII/CIRAD, 2 Place Pierre Viala, Montpellier 34060, France. bibi.fabien@hotmail.com.
authors.forename: Fabien
authors.initials: F
authors.lastname: Bibi
authors.affiliation: Joint Research Unit Agropolymers Engineering and Emerging Technologies, UMR 1208 INRA/SupAgroM/UMII/CIRAD, 2 Place Pierre Viala, Montpellier 34060, France. maud.villain@unistra.fr.
authors.forename: Maud
authors.initials: M
authors.lastname: Villain
authors.affiliation: Joint Research Unit Agropolymers Engineering and Emerging Technologies, UMR 1208 INRA/SupAgroM/UMII/CIRAD, 2 Place Pierre Viala, Montpellier 34060, France. c-guillaume@univ-montp2.fr.
authors.forename: Carole
authors.initials: C
authors.lastname: Guillaume
authors.affiliation: B. SORLI, Institut d'Electronique et des Systèmes, Université Montpellier 2, 860 Rue Saint-Priest, Montpellier 34090, France. brice.sorli@ies.univ-montp2.fr.
authors.forename: Brice
authors.initials: B
authors.lastname: Sorli
authors.affiliation: Joint Research Unit Agropolymers Engineering and Emerging Technologies, UMR 1208 INRA/SupAgroM/UMII/CIRAD, 2 Place Pierre Viala, Montpellier 34060, France. gontard@univ-montp2.fr.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Gontard
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D058266:Dielectric Spectroscopy; D004553:Electric Conductivity; D006801:Humans; D011108:Polymers / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*
chemical_list: D011108:Polymers; D011506:Proteins
keywords: bio-sensor; dielectric and structure modification; dielectric permittivity and loss; physico-chemical properties; proteins; vapors and gases