Highly Sensitive and Selective Fluorescent Sensor for Distinguishing Cadmium from Zinc Ions in Aqueous Media

Abstract

A fluorescent sensor, QA, based on acetamidoquinoline with DPA as receptor, was synthesized. In aqueous buffer solution, QA demonstrates high selectivity for sensing Cd(2+) with about 40-fold enhancement in fluorescence quantum yield and picomolar sensitivity (K(d) = 0.25 +/- 0.03 pM). Moreover, sensor QA can distinguish Cd(2+) from Zn(2+) via two different sensing mechanisms (PET for Cd(2+); ICT for Zn(2+)), and the discrimination is even possible by "naked eyes".

A simple but highly selective and sensitive fluorescence reporter for toxic CdII ion via excimer formation

“…The past few years have witnessed a few numbers of sensory reports on the design and synthesis of fluorescent chemosensors for the detection of Cd II ions [29][30][31][32][33], and among them, Cd IItriggered monomer-excimer conversion is limited [34]. For the first time, we report Cd II -induced excimer formation of a biological photosensitizer, kynurenic acid (Scheme 1), a renowned antiexcitotoxic and anticonvulsant drug which is an end product of the normal metabolism of amino acid l-tryptophan [35].…”

BODIPY-based fluorometric sensor array for the highly sensitive identification of heavy-metal ions

“…The fluorescence properties of BODIPY are tunable by simple substitution at various positions of the difluoroboron dipyrromethene core [25][26][27][28][29][30][31]. Multi-pyridyl ligands, including DPA and its derivatives N,N-di(pyridin-2-ylmethyl)-ethane-1,2-diamine (DPEA) and N,N,N -tri(pyridin-2-ylmethyl)-ethane-1,2-diamine (TPEA), are well-known receptors for heavy-metal ions, such as Zn 2+ , Cd 2+ , Hg 2+ , Cu 2+ etc [32][33][34][35][36][37][38][39][40]. The DPA derivatives combine high affinities for a variety of heavy-metal ions with the capacity to perturb the fluorescence properties of BODIPY, making them the most promising candidates for the design of fluorometric sensor arrays for heavy-metal ions.…”

Fluorescent Studies of Salicylaldehyde and Other Related Carbonyl Compounds for the Selective and Sensitive Detection of Zinc(II) Ions in Aqueous Solution

“…Many fluorometric sensors have been developed based on the photo-physical changes that can occur when zinc forms a complex with a ligand [8]. These include photo-induced electron transfer (PET) [9], photo-induced charge transfer (PCT), intramolecular charge transfer (ICT) [10], excimerexciplex formation and extinction and fluorescence resonance energy transfer (FRET) [11]. Imines and hydrazones of salicylaldehyde occupy a prominent place among the various ligands that have been employed for the determination of zinc [12,13].…”