In a one-pot synthesis, we are able to produce spherical gold nanoparticles capped with antibiotics, without the use of other chemicals by using the antibiotic as the reducing agent. Antimicrobial testing showed that the cefaclor reduced gold nanoparticles have potent antimicrobial activity against Staphulococcus aureus and E. coli bacteria as compared to the cefaclor or gold particles alone. We propose to use SANS to probe the structure of these nanoparticle conjugates, including the size and shape of the nanoparticles produced as well as the thickness of the antibiotic layer on the gold nanoparticles. Additionally we aim to follow in situ the reduction reaction in order to shed light on the mechanism by which the reaction proceeds.