PERGAMON Carbon 38 (2000) 495–499 Amorphous hydrogenated carbon doped with copper as antifungal protective coating a b, a * Vladimir I. Ivanov-Omskii , Ludmila K. Panina , Sergey G. Yastrebov a Ioffe Physico-Technical Institute RAS, Polytechnicheskaya 26, 194021 St. Petersburg, Russia b St. Petersburg State University, Department of Biophysics, Universitetskaya emb.7 /9, 199034 St. Petersburg, Russia Received 11 May 1999; accepted 21 May 1999 Abstract We report on the fungistatic properties of amorphous hydrogenated carbon doped with copper. It is clearly demonstrated that copper forms clusters with sizes of some nanometers. These clusters are distributed homogeneously over an amorphous carbon matrix. Doped films, in contrast with undoped ones, inhibit fungi growth at the film’s surface. This observed phenomenon is promising for the practical application of amorphous carbon films as a protective media against biodeterioration.  2000 Elsevier Science Ltd. All rights reserved. Keywords: A. Amorphous carbon; B. Plasma sputtering; C. Transmission electron microscopy (TEM); Optical microscopy; D. Biocompatibility 1. Introduction as a toxic agent for microorganisms. A mechanism of copper liberation from the a-C:H matrix is discussed. The unique nature of novel allotropic carbon modi- Our goal is to demonstrate quite a challenge of high fications and related phases, including diamond-like (DLC) technology of creation of a-C:H-based composites to create and amorphous carbons [1], accounts for the possible substances operating as active barriers against biological interest in their effect on living matter. Our goal is to attack of microorganisms which normally play an im- demonstrate a new biological property of hydrogenated portant role in natural environments in recycling the amorphous carbon (a-C:H)-based composites – to be an elements of the Earth’s crust. These microorganisms, active barrier against a biological attack of microorga- however, are able to cause biodeterioration. Among other nisms. These are responsible for undesirable biodeteriora- problems necessitating creation of a substance having tion, which is known to be a scourge to up-to-date high protective abilities, is the possible toxic damage to higher technology products operating in closed spaces of satel- animals and human beings. We selected a carbon-based lites, aircraft, submarines etc. DLC and a-C:H films are technology of ion sputtering of a carbon-based target as a known to be good protectors against environmental pollu- tool to produce a selective protective coating. Namely, we tants [2] and atmospheric waste as well. It was shown used a-C:H films, unique coatings, which can be applied to recently that modification of a-C:H films with nanosize many surfaces – plastics, ceramics, glass, etc. [1]. Copper copper clusters (a-C:H:Cu) by ion co-sputtering of copper trapped into the a-C:H matrix forms nanosize clusters and graphite targets allows producing films with entirely which modify integral characteristics of an a-C:H film [3]. new properties [3]. In the present paper we show that In the present work we modify the a-C:H matrix so as to among these properties is a strong fungistatic (i.e. inhib- impart to a-C:H, an additional property – fungistatic iting the fungal growth) effect of these films. We demon- action. This modification is of fundamental interest (pro- strate that copper nanosize clusters embedded in a-C:H act viding a possibility to study the interaction between fungi and nanoclusters) and will extend the area of application of a-C:H. Under normal conditions (temperature 208C, *Corresponding author. E-mail address: lu@lkp.usr.pu.ru (L.K. Panina). humidity 70–98%, pH56.5), copper clusters are inert 0008-6223 / 00 / $ – see front matter  2000 Elsevier Science Ltd. All rights reserved. PII: S0008-6223(99)00121-9