Fluorescent sensing of non-steroidal anti-inflammatory drugs naproxen and ketoprofen by dansylated squaramide-based receptors

Abstract

Bis-squaramide receptors L1–L4 bearing a dansyl moiety were synthesised and their potential applications as fluorescent probes towards non steroidal anti-inflammatory drugs naproxen and ketoprofen was investigated. A detailed photophysical characterization...

Potentiometric Sensing of Nonsteroidal Painkillers by Acyclic Squaramide Ionophores

“…As expected, under these novel experimental conditions, we were still able to calculate the association constants for the formation of the 1:2 adducts and to confirm the strong affinity of L4 toward the anionic guests, even in this more competitive medium. In the case of L5 , the results of the 1 H NMR solution studies with both NaNS and NaKF have been reported elsewhere and demonstrate the formation of 1:2 adducts with a stronger affinity to NS – …”

“…In comparison to L1 , the introduction of two supplementary H-bond donor groups in the structure of L5 resulted in a better sensitivity to KF – for membrane mb 5.2 (44.1 ± 4.5 mv/dec) containing 50 mol % cationic sites with respect to the ionophore (see Figure S22). Interestingly, while L1 forms with KF – only the 1:1 adduct in the DMSO/H 2 O mixture (see Table ), L5 forms the 1:2 adduct in the same experimental conditions . Similar to membranes based on L4 , the super-Nernstian slopes observed for the bigger-sized NS – anion indicate the formation of a mixture of 1:1 and 1:2 adducts inside the membrane phase.…”

“…L1 and L2 were synthesized as previously reported. , The synthesis of L5 has also been recently described . Receptors L3 and L4 were prepared by modification of the procedure reported in the literature and described in Scheme .…”

“…In the case of L5, the results of the 1 H NMR solution studies with both NaNS and NaKF have been reported elsewhere and demonstrate the formation of 1:2 adducts with a stronger affinity to NS − . 28 Potentiometric Properties of L1−L5-Based ISEs. The properties of 19 membranes (entries 1−19 in Table 1) of different compositions obtained by incorporation of 0.5 wt % L1−L5 inside PVC/TOP polymeric matrices were investigated and compared with the response of only the TDMACl (10 wt %) anion-exchanger-based membrane (entry 20, Table 1).…”

Squaramide-based receptors in anion supramolecular chemistry: insights into anion binding, sensing, transport and extraction

“…5). 19,20 The macrocyclic systems 16 and 17 have been found to be able to bind ketoprofen in its anionic form in a 1 : 1 stoichiometry in CH 3 CN/DMSO solution (1 : 1 v/v) with association constants of K ass = 9.4 Â 10 4 AE 0.6% and K ass = 8.3 Â 10 4 M À1 AE 1%, respectively. Receptors 19-24 were employed successfully for developing ion selective electrodes (ISEs) able to discriminate ketoprofen and naproxen in their anionic forms in real samples.…”