Biocompatible carbon-based screen-printed electrodes for the electrochemical detection of nitric oxide

We report in this study on the first use of carbon-based screen-printed electrodes (SPCEs) for the development of inexpensive, disposable and biocompatible electrochemical sensors for NO in solution. First, the screen printing electrode process was performed on two types of substrates and the chemical modification of the obtained electrodes was achieved in order to endow them with the desired sensitivity, selectivity and biocompatibility. The first important step in building the sensor system consisted into transposing existing chemical modifications to design selective and sensitive coatings towards NO. The second major and novel step of this work was devoted to confer to the electrode material the desired biocompatibility character by overcoating the whole chemically modified SPCEs with an additional layer of poly-oxyethyleneglycol (PEG) polymers. Since the biocompatible property of materials is generally linked to their hydrophilic character, the biocompatibility of the designed electrodes was assessed by sessile drop contact angle measurements. Finally, the performances of the electrodes towards NO were evaluated by chronoamperometric measurements.