Inhibitory effect of silicon nanowires on the polymerase chain reaction

The effect of nanomaterials on biological reactions has received much attention. We report herein that silicon nanowires (SiNWs) inhibit the polymerase chain reaction (PCR). The inhibitory effect was found to be concentration-dependent, with a minimum inhibitory concentration of about 0.4 mg ml(-1). DNA polymerase, restriction endonucleases, lysozyme and horseradish peroxidase maintained their bioactivities after exposure to SiNWs. Also the interaction of SiNWs with primers and dNTP did not lead to decreased PCR yield. Compared to primers and dNTP, template DNA showed 4.7-10.5-fold greater adsorption on SiNWs. Template bound to SiNWs was ineffective in the PCR, whereas addition of free template to the PCR system increased the yield. The results of this work suggest that the inhibitory effect of SiNWs on the PCR was due to the selective adsorption of double-stranded DNA on SiNWs, thereby decreasing the availability of template for the reaction.