A highly sensitive and selective chemosensor for Pb²⁺ based on quinoline–coumarin

Abstract

In this study, a highly sensitive and selective fluorescent chemosensor, ethyl(E)-2-((2-((2-(7-(diethylamino)-2-oxo-2H-chromene-3-carbonyl)hydrazono)methyl)quinolin-8-yl)oxy)acetate (1), was synthesized and characterized by 1 H NMR, 13 C NMR and ESI-MS. Sensor 1 showed an "on-off" fluorescence response to Pb 2+ with a 1 : 1 binding stoichiometry in CH 3 CN/HEPES buffer medium (9 : 1 v/v). The detection limit of sensor 1 to Pb 2+ was determined to be 0.5 mM, and the stable pH range for Pb 2+ detection was from 4 to 8.

Spiropyran–Merocyanine Based Photochromic Fluorescent Probes: Design, Synthesis, and Applications

“…Being one of the heavy metal ions, Pb 2+ has received significant attention due to its essential role in various fields and its high toxicity. Excessive intake of this ion may lead to muscle paralysis, mental retardation, and memory loss, particularly in children . Therefore, an effective platform is required for the recognition of Pb 2+ .…”

“…Excessive intake of this ion may lead to muscle paralysis, mental retardation, and memory loss, particularly in children. 53 Therefore, an effective platform is required for the recognition of Pb 2+ .…”

Mo(vi) complexes of amide–imine conjugates for tuning the selectivity of fluorescence recognition of Y(iii) vs. Pb(ii)

“…Comparison with other pioneering Y 3+ and Pb 2+ probes [62][63][64][65][66][67][68][69][70][71] Trace level determination of Y 3+ and Pb 2+ using Mo(VI) complexes (M1 and M2) by uorescence method is compared with available pioneering probes and presented in Tables S1 and S2, [62][63][64][65][66][67][68][69][70][71] (ESI). † A closer look reveals that some probes may have better LOD but the method either involves uorescence Scheme 2 Plausible sensing mechanism.…”

8‐Hydroxyquinoline Fluorophore for Sensing of Metal Ions and Anions

“…Fluorescent chemosensor 52 ( Figure 50) has been shown red-shift from 440 nm to 465 nm and a change in colour from bright yellow to orange in the presence of Pb 2 + ions. [80] However, the fluorescence intensity of chemosensor 52 at 485 nm (λ ex : 440 nm) was quenched on incremental of Pb 2 + . The binding constant K a as well as LOD has been determined to be respective 2 × 10 3 M À 1 and 0.5 × 10 À 6 M.…”