Nanoparticle size effect on the amplification efficiency of Nano-PCR

We have found that the total surface areas of the gold nanoparticles (AuNPs) with different sizes added into the PCR reagent dominantly affect PCR amplification efficiency. Within a certain range of concentration, the larger the total surface areas of the AuNPs, the higher the amplification efficiency would be. This was confirmed by employing AuNPs with the diameter of 13, 20 and 30 nm added in PCR reagent in the conditions of the same total volume amount of AuNPs, and the fixed AuNPs concentration of 0.16 nM. The PCR efficiency could be improved by 5.9 cycle numbers with the AuNPs added compared to that without AuNPs. With the increase of the total surface area at 5.33 times, the difference of efficiency under same PCR condition with same 10⁷ copies of DNA can be upto 3.7 cycle numbers.