A highly sensitive and selective colorimetric and off–on fluorescent chemosensor for Cu2+ based on rhodamine 6G hydrazide bearing thiosemicarbazide moiety

Supra-Carbon Dots Formed by Fe3+-Driven Assembly for Enhanced Tumor-Specific Photo-Mediated and Chemodynamic Synergistic Therapy

“…The Supra-CDs (Fe-Ce6-RCDs) can be obtained by a facile assembly approach through mixing Fe 3+ solution and Ce6-RCDs dispersion followed by the modification with poly­(ethylene glycol) (PEG) using thiol-terminated PEG (SH-PEG) to further ameliorate their stability and biocompatibility (Scheme a). As depicted in Figure a,b, the TEM measurements show that the average size of Fe-Ce6-CDs NPs increases from 3.46 nm to about 36.84 nm of Ce6-CDs, which fulfills the requirements for extending the blood circulation time and effective accumulation in tumors due to the EPR effect. , Figure c shows that the hydrodynamic diameter of Fe-Ce6-RCDs is around 60 nm, and this larger value than that observed from TEM can be ascribed to the formation of a hydration layer outside the NPs in aqueous solution for the dynamic light scattering (DLS) experiment and the particle shrinkage during the drying process for the TEM sample preparation. − Moreover, the high-angle annular dark-field (HAADF) and the corresponding energy-dispersive X-ray (EDX) elemental mapping images reveal the evenly distribution of C, N, O, and Fe in Fe-Ce6-RCDs (Figure d), verifying the successful assembly of Fe 3+ and Ce6-RCDs. The content of Fe in Fe-Ce6-RCDs was calculated to be 3.2% (mass percentage) by inductively coupled plasma optical emission spectroscopy (ICP-OES).…”

“…As depicted in Figure 1a,b, the TEM measurements show that the average size of Fe-Ce6-CDs NPs increases from 3.46 nm to about 36.84 nm of Ce6-CDs, which fulfills the requirements for extending the blood circulation time and effective accumulation in tumors due to the EPR effect. 51,52 Figure 1c shows that the hydrodynamic diameter of Fe-Ce6-RCDs is around 60 nm, and this larger value than that observed from TEM can be ascribed to the formation of a hydration layer outside the NPs in aqueous solution for the dynamic light scattering (DLS) experiment and the particle shrinkage during the drying process for the TEM sample preparation. 53−55 Moreover, the high-angle annular dark-field (HAADF) and the corresponding energy-dispersive X-ray (EDX) elemental mapping images reveal the evenly distribution of C, N, O, and Fe in Fe-Ce6-RCDs (Figure 1d), verifying the successful assembly of Fe 3+ and Ce6-RCDs.…”

Thiocarbazone‐appended coumarin: An easily accessible ratiometric fluorescent chemosensor for multianalyte (Zn2+ and Cu2+) systems

“…The ν(C=O), ν(C=N) and ν(C=S) bands of 1 were found at 1700, 1625 and 1535 cm −1 , respectively. 50 After Zn 2+ complexation, the ν(C=O) and ν(C=N) bands shifted to a lower wave number (1657 and 1610 cm −1 , respectively), indicating that the F I G U R E 2 Fluorescence emission spectra of the 10-µM probe 1 upon the addition of Cu 2+ (0-2 eq.) in dimethylformamide/ water (9/1, v/v) solution.…”

A Switchable Sensor for Cu2+ and Zn2+ Based on Xanthene Moietymaking a Path for a Complex Molecular Encryption System Based on Color and Fluorescent Change

“…These binding pockets have coordinating atoms like N, O, S, which facilitate coordinating metal cations like Cu 2+ , Ni 2+ , and Zn2 + . [1][2][3][4][5][6][7] The binding of analytes brings a physical and chemical change in the overall system, resulting in a rise in the signal detected by optical probes. Czarnik and coworkers were among the first who utilized the close and open ring feature of rhodamine B hydrazide as a sensor for Cu 2+ .…”