Enhancement in the efficiency of polymerase chain reaction by TiO₂ nanoparticles: crucial role of enhanced thermal conductivity

Abstract

Improvement of the specificity and efficiency of the polymerase chain reaction (PCR) by nanoparticles is an emerging area of research. We observed that TiO₂ nanoparticles of ~ 25 nm diameter caused significant enhancement of PCR efficiency for various types of templates (namely plasmid DNA, genomic DNA and complementary DNA). By a series of experiments, the optimal TiO₂ concentration was determined to be 0.4 nM, which resulted in up to a seven-fold increase in the amount of PCR product. As much as 50% reduction in overall reaction time (by reduction of the number of cycles and the time periods of cycles) was also achieved by utilizing TiO₂ nanoparticles without compromising the PCR yield. Investigations of the mechanism of such PCR enhancement by simulations using the 'Fluent K epsilon turbulent model' provided evidence of faster heat transfer in the presence of TiO₂ nanoparticles. Consistent with these findings, TiO₂ nanoparticles were observed to augment the denaturation of genomic DNA, indicating more efficient thermal conductivity through the reaction buffer. TiO₂ nanoparticle-assisted PCR may be useful for profound reduction of the overall PCR reaction period and for enhanced amplification of DNA amplicons from a variety of samples, including GC-rich templates that are often observed to yield unsatisfactory results.