摘要
Fast and sensitive detection of dilute rare earth species still represents a challenge for an on-site survey of new resources and evaluation of the economic value. In this work, a robust and low-cost protocol has been developed to analyze the concentration of rare earth ions using a smartphone camera. The success of this protocol relies on mesoporous silica nanoparticles(MSNs) with large-area negatively charged surfaces, on which the rare earth cations(e.g., Eu^(3+)) are efficiently adsorbed through electrostatic attraction to enable a ‘‘concentrating effect''. The initial adsorption rate is as fast as 4025 mg(g min)^(-1), and the adsorption capacity of Eu^(3+)ions in the MSNs is as high as 4730 mg g^(-1)(equivalent to ～41.2 M) at 70 °C. The concentrated Eu^(3+)ions in the MSNs can form a complex with a light sensitizer of 1,10-phenanthroline to significantly enhance the characteristic red emission of Eu^(3+)ions due to an ‘‘antenna effect'' that relies on the efficient energy transfer from the light sensitizer to the Eu^(3+)ions.The positive synergy of ‘‘concentrating effect'' and ‘‘antenna effect'' in the MSNs enables the analysis of rare earth ions in a wide dynamic range and with a detection limit down to ～80 nM even using a smartphone camera. Our results highlight the promise of the protocol in fieldwork for exploring valuable rare earth resources.
Fast and sensitive detection of dilute rare earth species still represents a challenge for an on-site survey of new resources and evaluation of the economic value. In this work, a robust and low-cost protocol has been developed to analyze the concentration of rare earth ions using a smartphone camera. The success of this protocol relies on mesoporous silica nanoparticles(MSNs) with large-area negatively charged surfaces, on which the rare earth cations(e.g., Eu^(3+)) are efficiently adsorbed through electrostatic attraction to enable a ‘‘concentrating effect''. The initial adsorption rate is as fast as 4025 mg(g min)^(-1), and the adsorption capacity of Eu^(3+)ions in the MSNs is as high as 4730 mg g^(-1)(equivalent to ～41.2 M) at 70 °C. The concentrated Eu^(3+)ions in the MSNs can form a complex with a light sensitizer of 1,10-phenanthroline to significantly enhance the characteristic red emission of Eu^(3+)ions due to an ‘‘antenna effect'' that relies on the efficient energy transfer from the light sensitizer to the Eu^(3+)ions.The positive synergy of ‘‘concentrating effect'' and ‘‘antenna effect'' in the MSNs enables the analysis of rare earth ions in a wide dynamic range and with a detection limit down to ～80 nM even using a smartphone camera. Our results highlight the promise of the protocol in fieldwork for exploring valuable rare earth resources.
基金
supported by the start-up and OVPR seed Grant from Temple University
