This is as expected for the quasi-reversible electrochemistry of surface-bound electroactive species [11,17]. This behaviour of the polymeric material selleck Crizotinib in buffer together with the associated low redox potential make the PANI-PESA composite suitable as a platform for biosensor preparation.Figure 1.CV of PANI:PESA nanocomposite in (A) 1 M HCl and (B) in 0.1 M phosphate buffer (pH 6.5).Figure 2.SEM image of PANI:PESA showing ~90 nm (diameter) nanotubes.SEM images of PANI-PESA composite material are shown in Figure 2. Surface morphology showed homogeneity and formation of uniform nanotubes of ~90 nm in diameter. The TGA curve of PANI-PESA presented in Figure 3, shows that this material is stable up to 230 ��C and retains up to 80% of its initial weight till 250 ��C.
FTIR spectra in Figure 4 show that PANI-PESA nanocomposite material displayed all the characteristic peaks for polyaniline . The bands corresponding to the stretching vibrations of N-B-N and N=Q=N structure appeared at 1501 cm-1 and 1573 cm-1, respectively (-B- and =Q= stand for benzenoid and quinoid moieties
Semiconducting Inhibitors,Modulators,Libraries metal oxides have been known for decades to be Inhibitors,Modulators,Libraries good gas sensing materials. Ethanol sensors based on SnO2 thick films have been commercialized for years. In 1991, Yamazoe demonstrated that reduction in crystal size would significantly increase the sensor performance . This is because nanosized grains of metal oxides are almost depleted of carriers (most carriers are trapped in surface states) and exhibit much poorer conductivity than microsized grains in ambient air, hence, when exposed to target gases, they exhibit greater conductance changes as more carriers are activated from their trapped states to the conduction band than with microsized grains.
Thus, the technological challenge moved to the fabrication Inhibitors,Modulators,Libraries of materials with nanocrystals which maintained their stability over long-term operation at high temperature . The exploration of one-dimensional (1D) oxide nanostructures has been stimulated and facilitated by the convenience of obtaining large amounts of single crystalline nanowires/nanobelts via the vapor Inhibitors,Modulators,Libraries transport  and vapor-liquid-solid (VLS) methods . The Sberveglieri  and Yang  groups initiated the investigation of gas sensing properties of SnO2 nanobelts. Sberveglieri et al.
demonstrated the use of SnO2 nanowires as sensor materials showing prominent current changes towards ethanol and CO, respectively, in a synthetic air environment , while Yang et al. demonstrated the first photochemical NO2 nanosensors Cilengitide (based on individual SnO2 nanoribbons) operating at room temperature . In 2004, selleck inhibitor our group reported high-performance ZnO nanowire sensors with a low detection limit of 1 ppm ethanol at 300 ��C . Ever since then the number of reports on gas sensors based on 1D metal oxide nanostructures have been growing exponentially every year.