Processible polyaniline as an advanced potentiometric pH transducer. Application to biosensors.
An advanced potentiometric pH transducer based on processible polyaniline (PCPAn) is reported on. Both glassy carbon and screen-printed carbon electrodes modified with PCPAn by dip-coating exhibited a fully reversible potentiometric response of approximately 90 mV/pH unit over the range from pH 3 to 9. Such a significantly higher potentiometric response of PCPAn-modified electrodes as compared with those of existing devices is explained on the basis of the thermodynamics of polyaniline redox reactions. The PCPAn-based pH transducers exhibit both good operational stability and prolonged shelf life and display a negligible response toward singly charged cations. The new thick-film pH transducer was employed for designing a potentiometric biosensor for urea. In the model solution which mimics blood serum, the urea-sensitive electrode has a detection limit of 10(-5) M urea and a maximum response of approximately 120 mV. The attractive performance characteristics are advantageous over those of existing pH sensors and offer great promise for sensing and biosensing applications.
Karyakin
A A
AA
Faculty of Chemistry of M.V. Lomonosov Moscow State University, Russia. joewang@nmsu.edu
Vuki
M
M
Lukachova
L V
LV
Karyakina
E E
EE
Orlov
A V
AV
Karpachova
G P
GP
Wang
J
J
D000814:Aniline Compounds / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D011108:Polymers / Q000737:chemistry; D011199:Potentiometry; D014159:Transducers
D000814:Aniline Compounds; D011108:Polymers