Fluorescence molecular detection exhibits limited development in detection applications due to generally low sensitivity and narrow detection range.The heavily doped semiconductor nanostructures Cu2-xS with surface plasmon resonance effect and typical rare-earth-doped upconversion luminescent nanoparticles NaYF4∶Yb,Er were prepared,and further Cu2-xS/NaYF4∶Yb,Er film substrates were obtained by three-phase interfacial self-assembly method.Combined with finite element method simulations,the local electric field distributions around Cu2-xS were calculated for different placement situations.The plasmon-coupling effect generated between Cu2-xS nanodisks was investigated on the upconversion luminescence performance and the Raman signals.Based on the intense upconver-sion luminescence caused by the excellent synergetic localized surface plasmon resonance effect,a dual detection method of qualitative before quantitative detection of Rhodamine B using surface-enhanced Raman scattering signal monitoring and fluorescence sensing was established.The results show that the coupling of the Cu2-xS plasmonic layer with the NaYF4∶Yb,Er luminescent layer not only enables three orders of magnitude improvement of upcon-version emission,but also achieves the detection limit of 10-7 mol·L-1for molecular detection and obtains a broad linear response from 10-3 to 10-7 mol·L-1,and finally realizes the qualitative and quantitative bifunctionality of high-sensitivity accurate detection.
NETL
NSTL
维普
万方数据
