pH sensor preparation by ink-jet printing

Cilj ovog rada bio je dizajnirati pH senzor na vodljivom supstratu. Elektroda na vodljivom supstratu izvedena je srebrnim nanočesticama tehnologijom ink-jet printanja. Tako pripravljena elektroda modificirana je vodljivim polimerom na bazi polianilina (PANI), kako bi se ostvario pH osjetljiv sloj. Provedeno je i mjerenje pH osjetljivosti klasičnih disk elektroda, zlatne elektrode (Au) i elektrode od staklastog ugljika (GC). Elektrode su oslojene vodljivim polimerom (PANI) te je testirana njihova pH osjetljivost primjenom Britton-Robinsonovih pufera. Testiran je i odziv komercijalne staklene elektrode za mjerenje pH kako bi dobivene rezultate mogli usporediti s modificiranim disk elektrodama. Modifikacija elektroda dobivenih ink-jet printanjem prije elektrokemijskog oslojavanja polianilinom izvedena je komercijalnom tintom na bazi ugljika ili slojem epoksi-grafita. Elektrokemijsko formiranje polianilina ostvareno je iz otopine anilina pripravljene u klorovodičnoj kiselini, primjenom cikličke voltametrije. Tako su dobivene dvije modifikacije koje su podvrgnute potenciometrijskom mjerenju. Testiranje pripravljenih pH senzora provedeno je u neprotočnoj i protočnoj mjernoj ćeliji. Protočna mjerenja izvedena su metodom injektiranja u protok te metodom kontinuiranog protoka.The aim of this work was to design a pH sensor on the plastic flexible substrate. Silver nanoparticles based ink was used for made conductive electrode by ink-jet printing technology. The prepared electrode was modified by a conductive polymer based on polyaniline (PANI), to achieve a pH sensitive layer. Measurement of pH sensitivity was also performed for classical disc electrodes, gold electrodes (Au) and glassy carbon (GC) electrodes. The electrodes are coated by a conductive polymer (PANI) and their pH sensitivity was tested using Britton-Robinson's buffers. Response of commercial glass electrode for measuring pH was also tested in order to compare the results with the modified disk electrodes. Modification of electrodes obtained by ink-jet printing prior to electrochemical coating by polyaniline was performed by commercial carbon-based ink or epoxy-graphite layer. Electrochemical formation of polyaniline was made from aniline solution prepared in hydrochloric acid using cyclic voltammetry. Such two modifications were subjected to potentiometric measurement. Testing of the prepared pH sensors was performed in a standard no flow and flow measuring cell. Flow measurements were performed by the flow injection method and the continuous flow method