Study of the Synthesis and Application of a Fluorescence‐Enhanced Mg 2+ Probe

A novel polyhedral oligomeric silsesquioxane nanohybrid fluorescent sensor designed based on an osmotic mechanism for specific detection and intelligent scavenging of magnesium ions

BACKGROUND

Mg2+ has long been recognized as one of the most vital cations due to its diverse physiological and pathological roles, making it indispensable in both biomedical and biological research. Organic fluorescent sensors are commonly employed for Mg2+ detection, but they often lack high selectivity and exhibit poor hydrophilicity, limiting their biomedical applications.

RESULTS

Herein, we introduced a novel organic-inorganic hybrid fluorescence sensor, PFHBS, constructed on the POSS nanoplatforms. The efficient connection between PEGylated POSS and the small molecule sensor FHBS through Click chemistry enhances the selectivity and reduces interference, making this chemical sensor ideal for the accurate detection of Mg2+. Furthermore, the incorporation of POSS amplifies the ligand field effect of FHBS, making it more conducive to Mg2+ capture. The modification of PEG chains enhances the sensor's amphiphilicity, facilitating efficient cell penetration and effective Mg2+ detection at the biological level.

SIGNIFICANCE

Finally, relying on spontaneous permeation, coupled with its strong ligand field effect and excellent cell permeability, the chemosensor demonstrates the capability to intelligently remove excess Mg2+ from the body. It has been successfully applied to mitigate renal overload resulting from acute Mg2+ poisoning.

A "Turn-On" fluorescent probe for detection and removal of Zn2+ in aqueous and its application in living cells

Using 3-hydroxy-2-naphthoic acid hydrazine and 4-(diethylamino) salicylaldehyde. as raw materials, compound L with an acylhydrazones structure was synthesized. The structure of compound L was characterized by nuclear magnetic resonance spectroscopy, X-ray single crystal diffraction, Fourier transform infrared spectroscopy, and mass spectrometry. The results show that Compound L can quickly and selectively recognize zinc ions in the H₂O/DMSO (V:V = 3:7) solvent system. After that, the spectral performance of probe L was studied by fluorescence spectroscopy and UV-vis spectroscopy. The results show that the combination with Zn²⁺ can significantly enhance the fluorescence intensity of probe L while being almost unaffected by other coexisting ions. After that, Job's curve method, nuclear magnetic titration analysis, and mass spectrometry were used to study the binding mechanism of probe L and Zn²⁺. The results showed that probe L coordinated with Zn²⁺ is 1:1. The linear equations of different concentrations of Zn²⁺ and fluorescence intensity were obtained by fitting, and the detection limit of probe L for Zn²⁺ was determined to be 6.75 × 10^-9 mol/L. The experimental study of standard addition and recovery showed that probe L could be used for the quantitative detection of Zn²⁺ in natural water samples. After that, we prepared L-doped sodium alginate hydrogel (SAL). The research results show that SAL has obvious adsorption capacity for Zn²⁺ in solution, and the color change before and after adsorption can be easily distinguished by the naked eye under ultraviolet light. SEM-EDS study showed that the microscopic morphology and composition of SAL changed significantly before and after adsorption. This fluorescent probe can be used for detection and removal of Zn²⁺ in aqueous solution. Also, probe L is effective for sensing for zinc (II) in living tumor cells. Overall, this work allows us to obtain a great potential to be applied to detect and remove Zn²⁺.