RhB-encapsulated metal-organic cage as a dual-emission fluorescence sensor for detection of malachite green and glycine

RhB@ZrT-1-OH composite was constructed by introduction of Rhodamine B (RhB) into the cages of zirconiumbased metal-organic cage that had two fluorescence emission peaks at 466 and 612 nm upon excitation at 327 nm. The dual-emission fluorescence sensor exhibits ultra-high sensitive detection for malachite green (MG) and glycine (Gly) in phosphate buffer solution (pH = 6.86). RhB@ZrT-1-OH as a ratiometric fluorescence probe was applied to detect MG with a low LOD of 0.2879 mu M and presented obvious fluorescence visual changes from orange to purple to blue under 254 nm UV-vis lamp. Moreover, RhB@ZrT-1-OH also can be utilized as a turnon fluorescence sensor to recognize Gly with a low LOD of 0.3747 mu M and exhibits fluorescence color changes from orange to pink to purple. Notably, the corresponding test papers for sensing MG and Gly were designed for recognize the concentration of MG and Gly. Furthermore, the dual-emission fluorescence sensor can be used to detect MG and Gly in fish and human serum with high sensitivity and reliable. The possible detecting mechanisms of RhB@ZrT-1-OH for sensing MG and Gly were detailedly explored.

Automated summary

RhB@ZrT-1-OH composite was developed as a dual-emission fluorescence sensor for highly sensitive detection of MG and Gly, and corresponding test papers were designed for concentration detection.