Oxo-spirocyclic structure bridged ditopic Schiff base: A turn-on fluorescent probe for selective recognition of Zn(II) and its application in biosensing

Ratiometric Fluorescence Platform Based on Modified Silicon Quantum Dots and Its Logic Gate Performance

“…When SA was added into the SiQDs solution, the two absorption peaks shifted to 260 and 387 nm, indicating the amino groups on SiQDs can easily combine to aldehyde groups of SA and SiQDs-SA nanostructure with the CN Schiff base unit has been formed. 34 Upon the addition of Zn 2+ into the SiQDs-SA solution, the intensity of an absorption band at 387 nm decreased and its peak wavelength red-shifted to 395 nm. The intensity of absorption signal at short wavelength (260 nm) slightly increased, which also indicated the formation of complexed structure upon coordination of Zn 2+ with SiQDs-SA via imine-N, and aromatic-OH from the SA moiety.…”

“…In the absorption curve of SA (0.3 mM), two peaks at 245 and 320 nm were identified, which can be attributed to the π–π* transition of the aromatic ring structure and n−π* transition of CO. When SA was added into the SiQDs solution, the two absorption peaks shifted to 260 and 387 nm, indicating the amino groups on SiQDs can easily combine to aldehyde groups of SA and SiQDs-SA nanostructure with the CN Schiff base unit has been formed . Upon the addition of Zn 2+ into the SiQDs-SA solution, the intensity of an absorption band at 387 nm decreased and its peak wavelength red-shifted to 395 nm.…”

A highly sensitive and selective fluorescent probe for quantitative detection of Al3+ in food, water, and living cells

“…The detection limit (LOD) for Al 3+ was found to be 8.1 Â 10 À8 M by using DL ¼ 3s/k (where DL is the detection limit, s is the standard deviation of the blank solution and k is the slope of the calibration plot). The association constant (K B ) of probe 2a with Al 3+ was determined to be 1.89 Â 10 3 M À1 via the Benesi-Hildebrand equation [37][38][39] (see Fig. 4C).…”

Fluorescent Schiff base sensors as a versatile tool for metal ion detection: strategies, mechanistic insights, and applications

“…39 and Table 2). 157 In buffer solution (ethanol/Tris-HCl, v/v, 4/1), sensor 98 underwent fluorescence enhancement at 458 nm (l ex = 380 nm) with the addition of an increasing concentration of Zn 2+ and reached a plateau after the addition of 4 equivalents of Zn 2+ . The complex stoichiometry was 1 : 1 (98/Zn 2+ ) and the binding constant was 4.457 Â 10 5 M À1 as calculated using the Benesi-Hildebrand equation.…”