Silica-modified oligonucleotide-gold nanoparticle conjugate enables closed-tube colorimetric polymerase chain reaction.

A facile silica coating significantly enhances the thermal stability and polymerase chain reaction (PCR) compatibility of oligonucleotide-gold nanoparticle conjugates, thus enabling colorimetric detection of PCR results in a closed-tube format. This method is specific, sensitive, and generally applicable. Its simplicity, visual readout, and carryover contamination-free features hold promise for point-of-care or on-site DNA testing.