Polypyrrole–polyaniline–Au (PPy–PANi–Au) nano composite films for label-free electrochemical DNA sensing

Effective immobilization of DNA for development of polypyrrole nanowires based biosensor

“…The EI spectrum consists of two parts: a semicircle that characterizes charge transfer process and a linear region that characterizes diffusion process. In comparison with other immobilization techniques in which PPy synthesized in form of a membrane and/or the DNA strands were binded to the surface of the sensor by other ways [16,17], the method in this work was conducted in a very simple way due to the available of up-end -NH 2 groups created during the polymerization of the polymer. Such functional groups also facilitated the data transmission between the DNA strands and the surface of the transducer through the PPy NWs.…”

“…where ω = 2πf is the angular frequency, f is the frequency, n is a dimensionless CPE exponent or coefficient directly related to the degree of the surface roughness and inhomogeneity of the electrode surface which varies between 0 and 1 [17]. The parameter n determines the extent of the deviation from the Randles model.…”

Label-free electrochemical detection of methyltransferase activity and inhibitor screening based on endonuclease HpaII and the deposition of polyaniline

“…Polyaniline (PANI) has been considered as one of the most significant conducting polymers, due to its remarkable electrical, electrochemical, redox properties and good environmental stability (Amano et al, 1994). Owing to its excellent performance, PANI has been applied to the fields of electrocatalysis and electrochemical sensors (Hosseini et al, 2010;Tang et al, 2014;Wilson et al, 2010). DNA that have negative charges on its phosphodiester backbone make them promising templates for the synthesis of polyaniline.…”

Coaxial conducting polymer nanotubes: polypyrrole nanotubes coated with polyaniline or poly(p-phenylenediamine) and products of their carbonisation

“…PPy nanotubes guided by methyl orange (MO) have relatively uniform diameters and high aspect ratios (Wilson et al, 2012;Antonio et al, 2013;Škodová et al, 2013;Guo et al, 2014;Kopecká et al, 2014;Peng et al, 2014); they are not greatly contaminated by other morphologies, such as globular particles. They make a good substrate for surface modification.…”

“…It is recognised that any surface in contact with the reaction mixture used for the preparation of PANI becomes coated with a thin film of this polymer. This strategy was reported in the literature (Mi et al, 2008;Wilson et al, 2012;Radhakrishnan et al, 2013) and it is used in the present study for the surface modification of PPy nanotubes. Other approaches, using zincoxide template, have also been reported .…”