A Novel, Dual-Response Chemosensor Based on Ferrocene Derivative for the Selective Detection of Al³⁺ Ions :...

A new Chemosensor, 5-ferrocenylsalicylaldehyde-2-pyridinehydrazone (SP-Fc), was designed and synthesized by condensing 5-ferrocenylsalicylaldehyde with 2-hydrazinopyridine. Its structure was characterized by ¹H NMR, ¹³C NMR and HRMS. SP-Fc could be used to identify Al³⁺ through dual optical and electrochemical responses. Upon addition of Al³⁺, The probe exhibited a significant fluorescence enhancement attributed to CHEF and the inhibition of both PET and ESIPT processes. The probe specifically regonized Al^3 + in a wide pH range and had a well linear range (0-200 µM). Job's plot analysis revealed that the interaction of SP-Fc with Al³⁺ was 1:1 binding stoichiometry. The detection limit of probe for Al³⁺ was observed as low as 1.30 × 10^- 7 M. The response mechanism of SP-Fc to Al^3 + was confirmed through NMR titration experiment. Additionally, the electrochemical signals of SP-Fc in the presence of the Al³⁺ was shifted significantly compared with those of the other metal cations tested. Moreover, Confocal fluorescence microscopy imaging demonstrated that SP-Fc can monitor Al³⁺ in living MCF-7 cells with low cytotoxicity. This showcases SP-Fc's promise for biological system and analytical chemistry, providing a robust tool for Al^3 + detection in diverse settings.