Conclusions
In summary, we first engineered a well-defined molecular ruler based on the GNPs/GaAs plasmonic structure using DNA scaffold as a bridge at controlled intramolecular distance, enabling an enhanced PL emission from GaAs. We found that, upon increasing the number of DNA base, the intensity of the PL emission gradually decreased, thereby we proposed that the PL enhancement is resulted from the known as the mechanism of metal-enhanced fluorescence. It is believed that the reported DNA molecular-based modulation strategy is highly feasible for enabling the coupling of SP in the hybrid plasmonic nanostructures for many bio/nano photonic applications, such as optic biosensing and devices.