Antibacterial fullerene-based particles, termed nC(60), were coated onto a polystyrene surface to evaluate their ability to prevent biofilm formation by Neudomonas mendocina. Biofilm growth on this surface was assessed using ethidium bromide staining and SEM, and cell viability was determined using live/dead fluorescent cell staining. Unexpectedly, surfaces coated with nC(60) developed a biofilm earlier than the uncoated control, and a higher percentage of live bacteria. This shows that some antimicrobial nanomaterials may lose their efficacy when applied as coatings. The nC(60) coating appeared to encourage rather than discourage biofilm formation. Furthermore, the bacteria that adhered to the surface were not killed, implying that while nC(60) would not perform well in this application, the electronic properties of fullerenes and their apparent ability to encourage biofilm formation should be investigated for potential microbial fuel cell applications. (C) 2008 Elsevier Ltd. All rights reserved.