The role of diazonium interface chemistry in the design of high performance polypyrrole-coated flexible ITO sensing electrodes

• Published in: Electrochemistry communications Vol. 77; pp. 14 - 18
• Main Authors: Lo, Momath, Diaw, Abdou K.D., Gningue-Sall, Diariatou, Aaron, Jean-Jacques, Oturan, Mehmet A., Chehimi, Mohamed M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2017; Elsevier
• Subjects: Chemical Sciences; Diazonium; Electrografting; Flexible ITO; Lead; Material chemistry; Other; Polypyrrole; Sensors; Diazonium; Lead; Electrografting; Flexible ITO; Sensors; Polypyrrole
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2017.02.002

Benzene sulfonic acid-doped polypyrrole (PPyBSA) films were electrochemically prepared on aminobenzenediazonium-modified flexible ITO in aqueous media in a simple and efficient way. Diazonium electroreduction resulted in aminophenyl-modified ITO (ITO-NH2), which served as a platform for the electrodeposition of a PPyBSA layer. Without diazonium pretreatment, the PPyBSA coating delaminates readily upon sonication or during ultrahigh vacuum outgassing prior to XPS analysis. In contrast, a pretreatment involving electrografting for 45s at −800mV resulted in excellent adhesion of PPyBSA, which withstood 75min of ultrasonication. The robust ITO-NH2-PPy electrode was employed for the fast, simple and accurate detection of lead (II) by differential pulse voltammetry. The potentiometric response was linear in the Pb(II) concentration range 10−8 to 2.5×10−7mol·L−1 and the detection limit was 9.94×10−10mol·L−1 at S/N=3. This work demonstrates the central role of diazonium chemistry in producing an adhesive aryl monolayer on low-cost, flexible ITO electrodes, allowing the fabrication of robust, high-performance electrochemical-sensing conductive-polymer films. [Display omitted] •Aminophenyl monolayer from diazonium was electrografted on flexible ITO electrode.•Adhesion of polypyrrole is excellent on diazonium-modified ITO but fails on bare ITO.•Polypyrrole film on modified ITO served for nanomolar detection of lead in water.