Regulating Fluorescent Aptamer-Sensing Behavior of Zeolitic Imidazolate Framework (ZIF-8) Platform via Lanthanide Ion Doping

Abstract

Nanoscale metal−organic frameworks (NMOFs) have been proved to be effective quenching platforms for fluorescent detection of DNA via fluorophorequencher pairs. Zeolitic imidazolate framework-8 (ZIF-8) is one type of the most promising NMOFs because of its excellent biocompatibility and easy preparation. However, ZIF-8 is rarely used as platforms for fluorescence sensing of DNA because of its bad fluorescence quenching property. In this study, lanthanide ions were doped into ZIF-8 to regulate its fluorescence quenching behavior. The La 3+ doped ZIF-8 (ZIF-8-La) showed the best quenching efficiency on dyelabeled DNA. The signal-to-background ratio was around 3 times higher than ZIF-8. Furthermore, a core−shell La 3+ -doped ZIF-8 (CS-ZIF-8-La) was designed to modify more La 3+ on the surface of ZIF-8. Compared with ZIF-8-La, the CS-ZIF-8-La exhibited the same fluorescence sensing behavior toward positivedye-labeled DNA, but showed completely contrary quenching property on the negative-dye-labeled DNA. On the basis of this phenomenon, CS-ZIF-8-La was successfully used as quenching platform for designing a ratiometric sensor for DNA and microRNA.

Colorable Zeolitic Imidazolate Frameworks for Colorimetric Detection of Biomolecules

“…To realize the colorimetric detection of microRNA and DNA, the starches (amylopectin, dextrin, and amylose) or tannic acid are loaded in porous zeolitic imidazolate frameworks (ZIFs), respectively. ZIFs are porous crystalline materials prepared by the coordination of imidazolate ligands and metal ions. − ZIFs, especially ZIF-8, ZIF-67, and ZIF-90, have shown promising ability to load a wide range of guests (such as nanoparticles, drugs, enzymes, etc.) without the change of conformations of the guests. − The prepared starch@ZIFs (or tan@ZIFs) are wrapped by aptamers as biogates (Figure A).…”

Metal‐Organic Frameworks‐Based Fluorescent Nanocomposites for Bioimaging in Living Cells and in vivo†

“…Wang and co‐workers developed a La 3+ doped ZIF‐8, which had a quenching effect on positive‐dye and negative‐dye‐labeled DNA and was used for microRNA imaging in living cells. [ 91 ] As shown in Figure 5B, the ratiometric detection of DNA could be achieved by ZIF‐8‐La with different dye‐labeled probes. The fluorescence intensity of the negatively charged fluorophore decreased, while the fluorescence intensity of the positively charged fluorophore increased.…”

DNA adsorption on nanoscale zeolitic imidazolate framework-8 enabling rational design of a DNA-based nanoprobe for gene detection and regulation in living cells

“…This may also explain the lack of applications of ZIF-8 for turn-on uorescent detection. 42 Thus, an additional quencher is required to design a uorescent sensor. 43 We also noticed that the uorescence intensity of C15-FAM and G15-FAM was obviously enhanced aer absorption on ZIF-8 ( Fig.…”

“…This could be explained by the strong electrostatic interaction of FAM uorophore with ZIF-8 that might disrupt its electron transfer toward DNA nucleobase, thus resulting in the uorescence recovery. 42,44 We next studied the loading capacity by xing FAM-labeled homo-DNAs at 100 nM (Fig. 2B).…”