Anti-Bacterial and Anti-Fouling Capabilities of Poly(3,4-Ethylenedioxythiophene) Derivative Nanohybrid Coatings on SUS316L Stainless Steel by Electrochemical Polymerization.

Chuan-Chih Hsu,Xin-Yao Peng,Ming-Chi Yung,Yu-Wei Cheng,Che-Chun Liu,Ting-Yu Liu

doi:10.3390/polym12071467

Abstract

We have successfully fabricated poly(3,4-ethylenedioxythiophene) (PEDOT) derivative nanohybrid coatings on flexible SUS316L stainless steel by electrochemical polymerization, which can offer anti-fouling and anti-bacterial capabilities. PEDOT derivative nanohybrids were prepared from polystyrene sulfonates (PSS) and graphene oxide (GO) incorporated into a conducting polymer of PEDOT. Additionally, the negative charge of the PEDOT/GO substrate was further modified by poly-diallyldimethylammonium chloride (PDDA) to form a positively charged surface. These PEDOT derivative nanohybrid coatings could provide a straightforward means of controlling the surface energy, roughness, and charges with the addition of various derivatives in the electrochemical polymerization and electrostatically absorbed process. The characteristics of the PEDOT derivative nanohybrid coatings were evaluated by Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), water contact angle, and surface potential (zeta potential). The results show that PEDOT/PSS and PEDOT/GO nanohybrid coatings exhibit excellent anti-fouling capability. Only 0.1% of bacteria can be adhered on the surface due to the lower surface roughness and negative charge surface by PEDOT/PSS and PEDOT/GO modification. Furthermore, the anti-bacterial capability (7 mm of inhibition zone) was observed after adding PDDA on the PEDOT/GO substrates, suggesting that the positive charge of the PEDOT/GO/PDDA substrate can effectively kill bacteria (Staphylococcus aureus). Given their anti-fouling and anti-bacterial capabilities, PEDOT derivative nanohybrid coatings have the potential to be applied to biomedical devices such as cardiovascular stents and surgical apparatus.

Highlights

In recent decades, the development of human medical care has been paid increasing attention.In relation to this, films with anti-bacterial coatings have been widely studied, including antibiotic materials, silver nanoparticles, copper nanoparticles, metal ions, and carbon nanotubes [1,2,3,4]
The characteristics of the PEDOT derivative nanohybrid coatings were evaluated by Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), water contact angle, and surface potential
When the graphene oxide (GO) nanosheets were used in the PEDOT nanohybrid system, the Raman spectrum of the PEDOT/GO nanohybrid coating was similar to that of the PEDOT/polystyrene sulfonates (PSS)

Summary

Introduction

Films with anti-bacterial coatings have been widely studied, including antibiotic materials, silver nanoparticles, copper nanoparticles, metal ions, and carbon nanotubes [1,2,3,4]. It is Polymers 2020, 12, 1467; doi:10.3390/polym12071467 www.mdpi.com/journal/polymers. Polymers 2020, 12, 1467 well-known that anti-bacterial materials use surface charges to improve anti-bacterial activities through the interaction with the different surface charge of the bacterial cell wall [5]. Poly(3,4-ethylenedioxythiophene) (PEDOT), a conducting conjugated polymer, has been widely used in various applications due to its excellent properties, including flexibility, chemical stability, high optical transparency, and good conductivity [8]. Conductive PEDOT-based derivatives, such as electrode films doped with poly(4-styrenesulfonate)

Methods

Results

Conclusion