Electrochemical/electrospray mass spectrometric studies of electrochemically stimulated ATP release from PP/ATP films

Polypyrrole (PP)/adenosine triphosphate (ATP) was chosen as a conducting polymer/anionic drug model to serve as a bioactive releasing material for ATP. The process of ATP release from PP/ATP films was investigated for the first time by electrochemical electrospray ionization mass spectrometry (EC/ESMS). This technique allowed the simultaneous and direct detection of ATP and its related species during electrochemical release. In the experiments, suitable solvent conditions were found for both the electrochemical release and the electrospray mechanisms. EC/ESMS results showed that continuous potential cycles allowed a higher ATP release rate than potential steps. It was also found that the film thickness is an important factor affecting the rate and the amount of electrochemical ATP release.