Chemically modified platinum screen-printed electrodes for electrochemical detection of acetylene

A three-electrodes potentiostatic cell was fabricated for acetylene detection in the range of 500 to 10000 ppm. The working electrode (sensing) was fabricated by depositing gold on Teflon electrodes. The auxiliary (counter) and the reference electrodes were defined on Al2O3 using platinum serigraphic paste. The platinum screen-printed electrodes were chemically modified by dipping in 1HF(49%):10H2O solution (d-HF) for times ranging from 10 to 120 min to obtain a three-electrodes potentiostatic cell for acetylene detection. Cyclic voltammetry indicated voltage-separation decreasing of the redox peaks and peak-current increasing when time in d-HF was increased. Surface morphology has changed after dipping in d-HF. It was noteworthy that valley-to-peak height and valley area increased, which meant better performance of the auxiliary and reference electrodes. As a result, a stable electrochemical sensor was fabricated with a detection limit of 500 ppm for acetylene dissolved in argon.