Abstract: Silver-coated proteins, being dissolvable or suspendable in aqueous media and/or retaining a biological activity of the protein and a process for preparing same are disclosed. Further disclosed are modified proteins which have a reducing moiety attached to the surface thereof and a process for preparing same. The modified proteins can be utilized for obtaining the silver-coated proteins. Further disclosed are a pharmaceutical composition containing and a method of treating bacterial and fungal infections utilizing biologically active silver-coated hydrogen peroxide producing enzymes such as glucose oxidase. Further disclosed are conductive elements that comprise the silver-coated proteins disclosed herein and electronic circuits containing same. Further disclosed are electrodes having the silver-coated proteins deposited thereon and biosensor systems utilizing same for determining a level of an analyte in a liquid sample.