Detection of DNA Hybridization Using ZnS:Mn²⁺ Nanowires/SiO₂ Core/Shell Nanocomposites and Au Nanoparticles

The ZnS:Mn²⁺ nanowires (NWs)/SiO₂ nanocomposites and Au nanoparticles (NPs) were used for the first time as donors and acceptors to detect DNA hybridization based on the mechanism of fluorescence resonance energy transfer (FRET). The ZnS:Mn²⁺ NWs/SiO₂ core/shell nanocomposites with the average diameter of 25 nm were synthesized by the Stöber method. The Au NPs with the average diameter of 19 nm were prepared by the seed-mediated growth method. The fluorescence intensity of ZnS:Mn²⁺ NWs/SiO₂–dsDNA–Au NPs conjugates decreased extremely compared with that of ZnS:Mn²⁺ NWs/SiO₂–DNA conjugates, indicating that FRET occurred between the ZnS:Mn²⁺ NWs/SiO₂ nanocomposites and Au NPs. When the target DNA sequence was added, the fluorescence intensity was restored. Thus, the selective hybridization of the probe DNA to the target DNA can be used for detecting the target DNA.