**5. Conclusions**

PANI and P3ABA both demonstrated bactericidal activity against *E. coli* and *S. aureus* in suspension and as part of an absorbent surface, with greater activity being observed with P3ABA. PANI in films was not active against *E. coli* or *S. aureus,* while P3ABA in films reduced the viability of *E. coli* after a 24 h treatment. The results that are presented in this work support the use of P3ABA to create contamination resistant surfaces.

**Acknowledgments:** The authors are grateful for research funding from both the New Zealand Ministry of Business, Innovation and Employment (MBIE) for research programmes UOAX0812 and UOAX1410, and the University of Auckland's Vice Chancellors Strategic Development Fund, gran<sup>t</sup> number 23563. The authors are grateful for funding (University of Auckland, SMS Publication Bursary) covering the costs to publish in open access. The authors thank Sudip Ray, Adeline Le Cocq, Chris Wilcox and Walt Wheelwright for purified PANI and P3ABA.

**Author Contributions:** Julia Robertson and Simon Swift conceived and designed the experiments; Julia Robertson performed the experiments and analysed the data; Marija Gizdavic-Nikolaidis contributed materials and advised on the chemistry aspects; Julia Robertson wrote the paper.

**Conflicts of Interest:** The authors declare no conflict of interest. The founding sponsors had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the decision to publish the results.
