Ratiometric and Highly Selective Fluorescent Sensor for Cadmium under Physiological pH Range:  A New Strategy to Discriminate Cadmium from Zinc

Abstract

In a neutral aqueous environment, a new ratiometric Cd2+ fluorescent sensor 1a can successfully discriminate Cd2+ from Zn2+ by undergoing two different internal charge transfer (ICT) processes, and the high selectivity of sensor 1a to Cd2+ over some other metals was also observed. Moreover, through structure derivation and a series of NMR studies, the unique role of the 2-picolyl group (the part in red in the abstract graphic) in the sensor 1a-Cd2+ complexation was disclosed.

Development of a fiber-optic chemical sensor for the detection of cadmium

“…The detection of cadmium using chemical methods is now new and several cadmium sensors based on fluorescence or surface plasmon resonance detection have been reported [2][3][4][5][6][7][8][9][10][11]. However, there are weaknesses with them and their application and most are not suitable for use in the field and often require extraction of samples prior to manipulation and analysis.…”

A fluorescent and colorimetric chemosensor for nitric oxide based on 1,8-naphthalimide

“…Another one is using transition metal complexes as NO receptors [10]. In our previous studies, various ligands were conjugated to 1,8-naphthalimide which is characteristic of an intramolecular charge transfer (ICT) chromophore with desirable photophysical properties such as a large Stokes' shift and long emission wavelength [11,12] to form a number of colorimetric and ratiometric fluorescent chemosensors for transition metal ions such as Cu(II) [13,14], Zn(II) [15], Cd(II) [16] and Ag(I) [17].…”

Acridine-derivated receptor for selective mercury binding based on chelation-enhanced fluorescence effect

“…Increasing attention has been given to the exploitation of a simple synthesis reagent and the development of a rapid, sensitive, and practical fluorescence analysis method to determine heavy metal ions [2]. An important practical challenge to achieving this goal is devising water-soluble fluorescent dyes that detect metal ions selectively over other competing contaminants of metal ions [3,4]. The most common fluorescent probes undergo nonspecific quenching with heavy metal analytes, such as Hg 2 þ , Ag þ , and Pb 2 þ [5][6][7].…”