Optimized protocol for the preparation of multi-walled carbon nanotube:polystyrene transducers for electrochemical sensing

Abstract

A practical method is presented to prepare films of a composite material constituted of multi-walled carbon nanotubes (MWCNTs) and polystyrene (PS) that are used for transduction applications. The method, which can be carried out by employing usual lab equipment, is simple, low-cost, rapid, and nonpolluting. Furthermore, it is compatible with microelectronic fabrication technology and is scalable for mass production. For designing this method, we studied how the number of drop-casted composite layers, the temperature used for curing the samples, and the duration of this thermal treatment influence on the electrochemical performance of a Si/SiO₂/Au/MWCNT:PS electrode. The optimum electrochemical responses of the Si/SiO₂/Au/MWCNT:PS electrode were obtained with films prepared with four layers of MWCNT:PS composite, each cured at 80 °C for 15 min. Under these conditions, the MWCNT walls are exposed and readily accessible for subsequent functionalization.

Keywords:

• Carbon nanotubes:polystyrene composite
• cyclic voltammetry
• electrochemical sensor
• multi-walled carbon nanotubes
• transducer

Acknowledgemnts

Special thanks are extended to E. Mendoza and C. Fernández-Sánchez for the thoughtful comments and support. Most of the experimental activities of this work were developed at the Centre de Recerca en Nanoenginyeria (CRnE) of the Universitat Politècnica de Catalunya, and at the Instituto de Microelectrónica de Barcelona - Centro Nacional de Microelectrónica, IMB-CNM (CSIC). This work was concluded in the context of the Project UES-PII-20-UAH-LCR-01.

Declaration of interest

The authors declare no competing interests.

Additional information

Funding

M. R. Baez-Gaxiola gratefully acknowledges the graduate grant from the Mexican Consejo Nacional de Ciencia y Tecnología (CONACYT).