The Role of 8-Amidoquinoline Derivatives as Fluorescent Probes for Zinc Ion Determination

Abstract

Mass-spectrometry-based and X-ray fluorescence-based techniques have allowed the study of the distribution of Zn2+ ions at extracellular and intracellular levels over the past few years. However, there are some issues during purification steps, sample preparation, suitability for quantification, and the instruments’ availability. Therefore, work on fluorescent sensors based on 8-aminoquinoline as tools to detect Zn2+ ions in environmental and biological applications has been popular. Introducing various carboxamide groups into an 8-aminoquinoline molecule to create 8-amidoquinoline derivatives to improve water solubility and cell membrane permeability is also a recent trend. This review aims to present a general overview of the fluorophore 8-aminoquinoline and its derivatives as Zn2+ receptors for zinc sensor probes. Various fluorescent chemosensor designs based on 8-amidoquinoline and their effectiveness and potential as a recognition probe for zinc analysis were discussed. Based on this review, it can be concluded that derivatives of 8-amidoquinoline have vast potential as functional receptors for zinc ions primarily because of their fast reactivity, good selectivity, and bio-compatibility, especially for biological applications. To better understand the Zn2+ ion fluorophores’ function, diversity of the coordination complex and geometries need further studies. This review provides information in elucidating, designing, and exploring new 8-amidoquinoline derivatives for future studies for the improvement of chemosensors that are selective and sensitive to Zn2+.

A Simple and Rapid Quinoline Schiff Base as a Fluorescent Probe for Zn2+ and Its Application in Test Strips

“…As far as we know, quinoline is a compound with low initial fluorescence, but it can form highly fluorescent complexes with metal ions. [30] Therefore, we designed a Schiff base compound (L) bearing a quinoline moiety and imine (Scheme 1), and fluorescence analysis showed that probe L could recognize Zn 2 + with high selectivity and was not affected by other metal ions in CH 3 OH/HEPES solution. In addition, the paper test was successfully carried out to detect zinc ions under 365 nm UV light.…”

Zinc ion detection using a benzothiazole-based highly selective fluorescence “turn-on” chemosensor and its real-time application

“…Colorimetric and uorescent chemosensors based on organic emissive molecules promise innovative solutions for sensor applications, since they are simple to use and can quickly provide chemical information. [15][16][17][18][19][20][21][22][23][24][25][26][27] A plethora of uorescent chemosensors [28][29][30][31][32][33][34][35][36][37] has been developed to date based on different uorophores, such as purine-based Schiff base, 38 rhodamine, 39 aminomethylnaphthol, 40 coumarin, 41 and quinoline containing acetyl hydrazone. 42 One frequent obstacle in searching for Zn 2+ -detection ligands is their apparent inability to distinguish Zn 2+ from its chemically identical neighbour, Cd 2+ .…”

Synthesis of 8-aminoquinoline chelating moieties for chemosensor molecules

“…8-Aminoquinolines have been proven to be potent ionophores, used in many metal-ion chelators, especially for Cu 2+ , Ni 2+ , Zn 2+ and Cd 2+ ions (see examples in Figure 1). [8][9][10][11][12][13] These analytes have gained significant importance recently, owing to their roles in neurobiology, immunology, and even in infectious diseases such as COVID-19. [14][15][16][17][18][19] Figure 1.…”