Polyazulene-based materials for heavy metal ion detection. 2. (E)-5-(azulen-1-yldiazenyl)-1H tetrazole-modified electrodes for heavy metal sensing

Azulene-based materials present very appealing properties for the preparation of advanced materials. They can be irreversibly electrooxidated, leading to polymers, which can be deposited on electrodes and modified. This paper shows several experiments concerning the preparation of modified electrodes based on (E)-5-(azulen-1-yldiazenyl)-1H-tetrazole (L). L has a tetrazole complexing unit, which can be attached to the electrode's surface and recognized. L has been deeply characterized by electrochemical techniques. Complexing modified electrodes have been prepared and tested in different conditions. Functional modified electrodes based on L obtained by controlled potential electrolysis were examined by AFM and SEM to see the influences of charge and potential on the deposited polyz films' morphologies. The modified electrodes prepared in different conditions have been tested for heavy metal ion sensing. The new azulene-based modified electrode demonstrated its feasibility for Pb ions analysis (detection limit of 5 × 10^-8 M, and linear domain between 5 × 10^-8 M and 10^-6 M) and potential use in future applications for real water samples analysis.