Gold nanoparticle wires for sensing DNA and DNA/protein interactions

The discontinuous Vertical Evaporation-driven Colloidal Deposition (dVECD) method has been used as a green technique for formatting nanoparticle wires by the direct deposition of nanoparticles from colloid suspensions onto hydrophilic substrates, without any lithographic procedures. Gold nanoparticles of different sizes are deposited into wire arrays for electronic detection of biological molecules. A sensitive detection of DNA molecules as low as ∼1 pM is achieved due to a high surface to volume ratio of the porous structures. The effects of the gold nanoparticles' size, DNA concentration, and DNA length on detection sensitivity of these gold nanoparticle wire sensors are discussed. Moreover, we can also detect the interaction between DNAs and proteins. Gold nanoparticle wires prepared by the nontoxic and simple dVECD are promising for detecting viruses involved in diseases.