A novel dual chemosensor for selective heavy metal ions Al3+, Cr3+ and its applicable cytotoxic activity, HepG2 living cell images and theoretical studies

Recent Developments in Colorimetric and Fluorometric Detection Methods of Trivalent Metal Cations (Al3+, Fe3+ and Cr3+) Using Schiff Base Probes: At a Glance

This review basically concerned with the application of different Schiff bases (SB) based fluorimetric (turn-off and turn-on) and colorimetric chemosensors for the detection of heavy metal cations particularly Al(III), Fe(III), and Cr(III) ions. Chemosensors based on Schiff bases have exhibited outstanding performance in the detection of different metal cations due to their facile and in-expensive synthesis, and their excellent coordination ability with almost all metal cations and stabilize them in different oxidation states. Moreover, Schiff bases have also been used as antifungal, anticancer, analgesic, anti-inflammatory, antibacterial, antiviral, antioxidant, and antimalarial etc. The Schiff base also can be used as an intermediate for the formation of various heterocyclic compounds. In this review, we have focused on the research work performed on the development of chemosensors (colorimetric and fluorometric) for rapid detection of trivalent metal cations particularly Al(III), Fe(III), and Cr(III) ions using Schiff base as a ligand during 2020-2022.

Heterocyclic Organic Compounds as a Fluorescent Chemosensor for Cell Imaging Applications: A Review

Fluorometric determination of different biologically, industrially, and environmentally important analytes is a powerful technique because this technique has excellent selectivity, high sensitivity, rapid photoluminescence response, low cost, applicability to bioimaging, and low detection limit. Fluorescence imaging is a powerful technique for screening different analytes in the living system. Heterocyclic organic compounds have been extensively used as a fluorescence chemosensor for the determination of different biologically important cations like Co2+, Zn2+, Cu2+, Hg2+, Ag+, Ni2+, Cr3+, Al3+, Pd2+, Fe3+ Pt2+, Mn2+, Sn2+, Pd2+, Au3+, Pd2+, Cd2+, Pb2+ and other ions in biological and environmental systems. These compounds also showed significant biological applications such as anti-cancer, anti-ulcerogenic, antifungal, anti-inflammatory, anti neuropathic, antihistaminic, antihypertensive, analgesic, antitubercular, antioxidant, antimalarial, antiparasitic, antiglycation, antiviral anti-obesity, and antibacterial potency. In this review, we summarize the heterocyclic organic compounds based on fluorescent chemosensors and their applications in bioimaging studies for the recognition of different biologically important metal ions.

A Significant Fluorescence Turn-On Probe for the Recognition of Al3+ and Its Application

An easy prepared probe, BHMMP, was designed and synthesized, which displayed a significant fluorescence enhancement (over 38-fold) and obvious color change in the recognition of Al³⁺. The binding ratio of probe BHMMP to Al³⁺ was determined as 1:1, according to Job plot. The binding mechanism was fully clarified by the experiments, such as FT-IR spectrum, ESI-MS analysis, and ¹H NMR titration. A DFT study further confirmed the binding mode of BHMMP to Al³⁺. The limit of detection (LOD) for Al³⁺ was determined as low as 0.70 µM, based on the fluorescence titration of BHMMP. Moreover, the results from real sample experiments, including real water samples, test papers, and cell images, well-demonstrated that BHMMP was capable of sensing Al³⁺ in environmental and biological systems.

A Review on Organic Colorimetric and Fluorescent Chemosensors for the Detection of Zn(II) Ions

Organic compounds display several electronic and structural features which enable their application in various fields, ranging from biological to non-biological. These compounds contain heteroatoms like sulfur, nitrogen and, oxygen, which provide coordination sites to act as ligands in the field of coordination chemistry and are used as chemosensors to detect various metal ions. This review article covers different organic compounds including Schiff bases, thiourea, pyridine, rhodamine, triazole, pyrene, coumarin, imidazole, diaminomaleonitrile, naphthoxazole, pyrimidine, thiophene, thioether, and other functional groups based chemosensors that contain heteroatoms like sulfur, nitrogen and, oxygen for fluorimetric and colorimetric detection of Zn(II) ions in different environmental, agricultural, and biological samples. Further, the sensing performances of these chemosensors have been compared and discussed which could help the readers for the future design of organic fluorescent and colorimetric chemosensors for the detection of Zn(II) ions. We hope this study will support the new thoughts to design a simple, efficient, selective, and sensitive chemosensor for the detection of Zn(II) ions in different samples (environmental, agricultural, and biological).

Novel fluorescent probes based on nitrogen–sulfur co-doped carbon dots for chromium ion detection

In this work, novel carbon dots codoped with nitrogen and sulfur (NSCDs) were used as fluorescent probes to detect Cr³⁺.

A pH tuning single fluorescent probe based on naphthalene for dual-analytes (Mg2+ and Al3+) and its application in cell imaging

In this study, a naphthalene Schiff-base P which serves as a dual-analyte probe for the quantitative detection of Al3+ and Mg2+ has been designed. The proposed probe showed an ''off-on'' fluorescent response toward Al3+ in ethanol-water solution (1 : 9, v/v, pH 6.3, 20 mM HEPES) over other metal ions and anions, while the detection by the probe could be switched to Mg2+ by regulating the pH from 6.3 to 9.4. The sensing mechanisms of P to Al3+/Mg2+ are attributed to inhibition of the photo-induced electron transfer (PET) process by the formation of 1 : 1 ligand-metal complexes. More importantly, the probe was applied successfully in living cells for the fluorescent cell-imaging of Al3+ and Mg2+.