Surface modification of platinum quartz crystal microbalance by controlled electroless deposition of gold nanoparticles and its enhancing effect on the HS-DNA immobilization

Quartz crystal microbalance (QCM) and colloid gold nanoparticles are the important techniques for DNA sensing. We successfully deposited gold nanoparticles on platinum QCM (Pt-QCM) based upon displacement reaction of electroless deposition. The deposition amount and size of gold nanoparticles could be controlled through choosing different experimental conditions. The HS-DNA immobilization amount on gold nanoparticles modified platinum QCM [(Au)Pt-QCM] was relative to the surface coverage and size of deposited gold nanoparticles. The maximum immobilization amount of HS-DNA was about threefold more than that on bare Pt-QCM.