We have decided to use pencil lead electrodes, which are low cost and easy to prepare also in large quantities allowing many tests to be performed simultaneously. Apart from low cost sensing applications pencil lead electrodes can be used as easily available, disposable sensors from high quality graphite(Witkowska . Softer leads (2 or even 8B), with higher graphite to filler content should be used for electrochemical applications ). Graphite's sp 2 hybridization should also allow for efficient modification with syringaldazine. Such electrodes can be easily fabricated by embedding the graphite rod from an automatic pencil in an insulating polymer, enclosing in a micropipette tip or as was done in this work in a glass capillary (Figure ).