Composites of Intrinsically Conducting Polymers as Sensing Nanomaterials

TLDR: The resonance-stabilized structure of ICPs allows for the incorporation of ions, nanoparticles, or nanowires of metals, metal oxides, carbon, or molecular species such as metallophthalocyanines or biologically active components such as enzymes, antibodies, and antigens.

Abstract: Composites of intrinsically conducting polymers (ICPs) are materials that utilize conjugated polymers and at least one secondary component that can be inorganic or organic materials or biologically active species. The goal is to produce a new composite material that has distinct properties that were not observed in the individual components. This may include either new or improved chemical properties that can be exploited for chemical or biological sensing. For example, adding carbon nanotubes tends to drastically influence the electrical and thermal conductivity of ICPs. A secondary aspect concerns the stabilization of the secondary component in the polymer matrix. Enhanced optical, electrical, or mechanical properties such as stiffness and strength are common. In some cases, the physical and chemical properties of the secondary component are much different after composite formation. For the purpose of this review we will primarily focus on the ICPs such as polyaniline, polypyrrole, and polythiophene and their derivatives. The resonance-stabilized structure of ICPs allows, for example, incorporation of ions, nanoparticles, or nanowires of metals, metal oxides, carbon, or molecular species such as metallophthalocyanines or biologically active components such as enzymes, antibodies, and antigens. 1 I some cases, the ICP will simply act as a template for the incorporation of the secondary component. In that case, the secondary component will impart the chemical properties required for chemical sensing. In other cases the materials are linked through electrostatic interactions which influence the electronic and physical properties of the materials used to prepare the composite.