Biphenyl-containing amido Schiff base derivative as a turn-on fluorescent chemosensor for Al³⁺ and Zn²⁺ ions

Abstract

A hydrazine derived Bis(2-hydroxybenzylidene)-[1,1'-biphenyl]-2,2'-dicarbohydrazide (sensor 1) has been synthesized and its sensing properties towards metal ions has been demonstrated using simple UV-visble spectroscopic, fluorometric technique and visible colour change. The...

A Simple and Rapid Quinoline Schiff Base as a Fluorescent Probe for Zn2+ and Its Application in Test Strips

“…The corresponding plot of fluorescence intensity versus Zn 2+ concentration was constructed, and a strong linear correlation (Y=‐81.23867+1.0517E8*X, R 2 =0.99591, Figure 3b) was observed over the range of 1~10 μM. Importantly, the remarkable limit of detection (LOD) for Zn 2+ using the rule of 3σ/slope, [40–42] was calculated to be 1.04×10 −7 M compared to the previously published probes [6,26,27,43–59] (Table 1). In addition, the association constant ( K ) for L− Zn 2+ complexation was determined by Benesi‐Hildebrand equation: $${{{{F}_{max}-{F}_{min}}\over{F-{F}_{min}}}={{1}\over{K\left[M\right]}}+1}$$ , [60] to be 3.496×10 4 M −1 (Figure S10), which confirms binding affinity of L towards Zn 2+ .…”

“…Meanwhile, the imine proton signal was weakened and resulted in a broader peak which confirmed the direct binding of nitrogen with Zn 2 + . [57,58] The IR and 1 H NMR data illustrated that the imine nitrogen and quinoline nitrogen are involved in coordination with Zn(II) center.…”

“…As we can see from Figure 8, only the test strip treated with Zn 2 + ions exhibited yellow fluorescence, indicating that such test strips have potential applications in the qualitative detection of Zn 2 + ions. [58,59]…”

Crystallographic elucidation of an aluminium-bound amido Schiff base chemosensor: a selective turn-on fluorescent chemosensor for Al3+ ions

“…to complex 1 solution, no spectral change was observed via UV-vis absorption spectroscopy, indicating that EDTA is unable to chelate the Al 3+ ion due to the high binding constant of complex 1. [59][60][61] In a similar manner, no change in the fluorescence emission of complex 1 was observed upon the addition of Na 2 EDTA (0-5 equiv.) when excited at 350 nm (Fig.…”

“…to complex 1 solution, no spectral change was observed via UV-vis absorption spectroscopy, indicating that EDTA is unable to chelate the Al 3+ ion due to the high binding constant of complex 1 . 59–61…”