Bioaffinity Sensing Using Biologically Functionalized Conducting-Polymer Nanowire

Abstract

A simple, one-step method for fabricating single biologically functionalized conducting-polymer (polypyrrole) nanowire on prepatterned electrodes and its application to biosensing was demonstrated. The biologically functionalized polypyrrole was formed by the electropolymerization of an aqueous solution of pyrrole monomer and the model biomolecule, avidin- or streptavidin-conjugated ZnSe/CdSe quantum dots, within 100 or 200 nm wide by 3 mum long channels between gold electrodes on prefabricated silicon substrate. When challenged with biotin-DNA, the avidin- and streptavidin-polypyrrole nanowires generated a rapid change in resistance to as low as 1 nM, demonstrating the utility of the biomolecule-functionalized nanowire as biosensor. The method offers advantages of direct incorporation of functional biological molecules into the conducting-polymer nanowire during its synthesis, site-specific positioning, built-in electrical contacts, and scalability to high-density nanoarrays over the reported silicon nanowire and carbon nanotube biosensors.

Use of Thin Sectioning (Nanoskiving) to Fabricate Nanostructures for Electronic and Optical Applications

“…[89] Incorporation of molecular recognition elements into semiconducting, conjugated polymer nanowires is relatively straightforward by synthesis, while modifications of carbon nanotubes and inorganic nanowires require functionalization of the surfaces, carried out post-fabrication. [90] Other possible uses for conjugated polymer nanowires are as tools for studying one-dimensional charge transport, [91] or as field-effect transistors, [92] actuators [93] or interconnects. [94] There is not yet a truly general technique for the fabrication of conjugated polymer nanowires.…”

The increasing importance of carbon nanotubes and nanostructured conducting polymers in biosensors

“…An example of this is where a pyrrole monomer and biomolecule receptor (avidin) were electropolymerised within 100 nm wide channels (130). When exposed to biotin−DNA, the conducting polymer nanowires generated a rapid change in resistance, with sensitivity as low as 1 nM.…”

Surface plasmon resonance-enhanced light interaction in an integrated ormocomp nanowire

“…Hence, they can be used in a variety of possible sensing applications. By exploiting their chemical selectivity, polymer nanowires can be used to detect a wide range of chemical compounds including toxics gases, metal ions, and DNA (Huang et al 2003;Wang et al 2002;Ramanathan et al 2005). Polymer nanowires have been studied for use as chemical sensors, biosensors, organic light emitting diodes, and organic solar cells (Huang et al 2003;Liu et al 2004;Ramanathan et al 2005).…”