Combination of PCR and dual nanoparticles for detection of Plasmodium falciparum.

Highly reactive particle-based DNA amplification was developed for the detection of the Pfg377 gene from P. falciparum gametocytes using functional magnetic latex particles (MLPs) and quantum dots encapsulated polymer particles (QDs-PPs). Firstly, MLPs were prepared from the precipitation of iron oxide, polymerization using initiator, and adsorption of aminodextran (AMD) so as to provide amino-functionalized MLPs. Furthermore, amino-containing polymer particles (PPs) were prepared by emulsifier-free polymerization and encapsulated with fluorescent quantum dots (QDs) for use as a signaling support. Subsequently, poly(maleic anhydride-alt-methyl vinyl ether) (PMAMVE) copolymer was effectively used for rapid and simple grafting of amino-modified DNA primers onto the surface of amino-functionalized particles thereby providing a promising method for particle immobilization. Herein, primer-grafted particles were applied in the amplification of the Pfg377 gene using the PCR approach. After amplification, PCR products containing PMAMVE-grafted MLPs and QDs-PPs were separated using a magnet and examined via a fluorescence microscope. PMAMVE-grafted particles were not found to inhibit the PCR reaction while facilitating efficient fluorescent detection of the PCR product. Results showed high sensitivity and specificity for the detection of amplified Pfg377 gene within only a few steps. This procedure represents a novel improvement to the post-amplification analysis.