Synergistic Enhancement of Fluorescence Through Plasmon Resonance and Interfacial Charge Transfer by AgNC@AgAux Core–Shell Quantum Dots

Abstract Bimetallic core–shell quantum dots (QDs) hold great promise in elucidating the bimetallic synergism and optoelectronic devices. The synthesis and properties of AgNC@AgAu x QDs of core–shell heterostructure are reported. Significantly enhanced photoluminescence emission on these heterostructures is observed. These enhancements are attributed to electron injection and the surface plasmon‐induced strong local electric field, which are observed through time‐resolved transient absorption spectroscopy. X‐ray absorption near edge structure spectra and density functional theory confirms the electron injection from the Ag core to the AgAu x shell. On the other hand, the plasmon resonance of the AgNC@AgAu x QDs has been studied by finite‐element method analysis and time‐resolved photoluminescence spectra. There are 94.06 times fluorescence enhancement and 32.40 times quantum yield improvement of oxygen content correlation compared to AgAu 3 QDs. It shows a perfect correlation coefficient of 98.85% for the detection of heavy metal Cu 2+ ions. Such Bimetallic core–shell heterostructures have great potential for future optoelectronic devices, optical imaging, and other energy‐environmental applications.