A novel rhodamine-based fluorescence chemosensor containing polyether for mercury (II) ions in aqueous solution

Abstract

publicado na web em 01/06/2017 A novel rhodamine-based Hg 2+ chemosensor P2 containing polyether was readily synthesized and investigated, which displayed high selectivity and sensitivity for Hg 2+ . Because of good water-solubility of polyther, the rhodamine-based chemosensor containing polyether can be used in aqueous solution. The sensor responded rapidly to Hg 2+ in pure water solutions with a 1:1 stoichiometry. Meanwhile, it indicated excellent adaptability and also the responsiveness.

Rhodamine-Appended Polymeric Probe: An Efficient Colorimetric and Fluorometric Sensing Platform for Hg2+ in Aqueous Medium and Living Cells

“…Considering the collective results, the chelation of CP2 with Hg 2+ was favorable via the "O" atom of the carbonyl group and the amino "N" atom of the rhodamine unit owing to the high affinity of Hg 2+ ions as a soft acid for N and O atoms (Figure 5A). 45 This showed that Hg 2+ coordinated with the • N−O • receptor under a suitable geometry conformation and resulted in a spirolactam ring-opening. 56,61 Moreover, we checked the 1 H NMR spectra of CP2 after the addition of Hg 2+ for further verification of the sensing mechanism but did not find any significant change in chemical shifts (data not shown here).…”

“…Additionally, CP2 exhibited a feeble absorption band at 560 nm, which could be credited to the existence of a minute amount of the ring-opened amide form of rhodamine in the pendant (Figure S8). 45 Before the implication of CP2 as a sensor, we have investigated the stability of the polymeric sensor in water with respect to time. For this, the absorption spectra of an aqueous solution of CP2 (1 mg/mL) were recorded at different time intervals from 0 to 24 h at pH 7.0 (Figure S9).…”

“…41 Over the past decade, there has been growing interest in the field of polymer-based sensors for detecting toxic Hg 2+ ions. 42,43 Although several polymers comprising Hg 2+ -recognition fluorophores have been fabricated and explored, most of them have drawbacks like selectivity, 44 sensitivity, 45 and moderate water solubility, 46 which limit their biological applications. Considering all of the facts, herein, we have designed a water-soluble polymeric sensor bearing rhodamine units attached to the side-chain tryptophan moieties in the polymer through an amide bond.…”

“…Still, many rhodamine-based chemosensors are accompanied by noticeable limitations such as minimal aqueous solubility, , tedious synthetic methods, , and poor sensing abilities including selectivity, sensitivity, and feasibility. , As an alternative, polymeric probes , consisting of molecular receptor units have been utilized recently to detect Hg 2+ ions in water since they offer improved aqueous solubility, enhanced biocompatibility, structural stability, and binding efficiency. , Interestingly, in several cases, after the attachment of fluorescent chromophores into the polymer side chain through covalent bonding, the polymeric probe exhibited dramatically higher fluorescence intensity than that of its monomeric unit of the same fluorophore concentration, , owing to the “structural self-quenching effect” . Over the past decade, there has been growing interest in the field of polymer-based sensors for detecting toxic Hg 2+ ions. , Although several polymers comprising Hg 2+ -recognition fluorophores have been fabricated and explored, most of them have drawbacks like selectivity, sensitivity, and moderate water solubility, which limit their biological applications.…”

Detection of Hg2+ in Aqueous Media by A New Xanthene Based Schiff Base Sensor

“…Colorimetric sensors such as triazine, coumarin, quinolone, rhodamine, and chromenylium-cyanine have been designed for detection of the transition metal ions in aqueous media (Aksuer et al, 2011Du et al, 2017Voutsadaki et al, 2010;;Wei et al, 2016). Hydroxybenzaldehyde Schiff bases derived from Rhodamine B, one of the most used probe structure, was enables Cu 2+ sensing via coordination of transition metal ion through phenolic oxygen and imine nitrogen atoms of the sensor because of its large association constant (Li et al, 2015;Tang et al,2011;Xiang et al, 2006).…”