A dual-model fluorescent Zn2+/Cu2+ ions sensor with in-situ detection of S2−/(PO4)− and colorimetric detection of Fe2+ ion

Dual-Mode Multiple Ion Sensing via Analyte-Specific Modulation of Keto-Enol Tautomerization of an ESIPT Active Pyrene Derivative: Experimental Findings and Computational Rationalization

A pyrene-based e xcited - state intramolecular proton transfer (ESIPT) active probe PMHMP was synthesized, characterized, and employed for the ppb-level, dual-mode, and high-fidelity detection of Cu²⁺ (LOD: 7.8 ppb) and Zn²⁺ ions (LOD: 4.2 ppb) in acetonitrile medium. The colorless solution of PMHMP turned yellow upon the addition of Cu²⁺, suggesting its ratiometric, naked-eye sensing. On the contrary, Zn²⁺ ions displayed concentration-dependent fluorescence rise till a 0.5 mole fraction and subsequent quenching. Mechanistic investigations indicated the formation of a 1:2 exciplex (Zn²⁺:PMHMP) at a lower concentration of Zn²⁺, which eventually turned into a more stable 1:1 (Zn²⁺:PMHMP) complex with an additional amount of Zn²⁺ ions. However, in both cases, it was observed that the hydroxyl group and the nitrogen atom of the azomethine unit were involved in the metal ion coordination, which eventually altered the ESIPT emission. Furthermore, a green-fluorescent 2:1 PMHMP-Zn²⁺ complex was developed and additionally employed for the fluorimetric analysis of both Cu²⁺ and H₂PO₄ ^- ions. The Cu²⁺ ion, owing to its higher binding affinity for PMHMP, could replace the Zn²⁺ ion from the preformed complex. On the other hand, H₂PO₄ ^- formed a tertiary adduct with the Zn²⁺-complex, leading to a distinguishable optical signal. Furthermore, extensive and organized density functional theory calculations were performed to explore the ESIPT behavior of PMHMP and the geometrical and electronic properties of the metal complexes.

Synthesis of a novel triphenylamine-based multifunctional fluorescent probe for continuous recognition application

In this paper, a novel fluorescent probe, TPA-PAT, with continuous recognition based on triphenylamine was designed, synthesized, and characterized by NMR, IR, and fluorescence spectrophotometry techniques.

Three-in-one type fluorescent sensor based on a pyrene pyridoxal cascade for the selective detection of Zn(ii), hydrogen phosphate and cysteine

A novel fluorescent receptor L was developed for the selective detection of important bioactive analytes.

Exploration of an easily synthesized fluorescent probe for detecting copper in aqueous samples

Bonding behavior and spectral response studies of an easily synthesized fluorescent probe for the detection of Cu²⁺ ions and CuO NPs in aqueous samples.

A Fluorescent Sensor for Al(III) and Colorimetric Sensor for Fe(III) and Fe(II) Based on a Novel 8-Hydroxyquinoline Derivative

A novel 8-hydroxyquinoline-based fluorescent and colorimetric chemosensor was designed, synthesized and fully characterized. The sensor showed high selectivity and sensitivity toward Al(3+) over other tested cations in EtOH/H2O (1:99, v/v) medium. The increase in fluorescence intensity was linearly proportional to the concentration of Al(3+) with a detection limit of 7.38 × 10(-6) M. Moreover, the sensor exhibited an obvious color change from yellow to black in the presence of Fe(2+) and Fe(3+) in EtOH/THF (99:1, v/v) solution. The absorbance changes showed a linear response to iron ions with the detection limits of 4.24 × 10(-7) M and 5.60 × 10(-7) M for Fe(2+) and Fe(3+), respectively. Thus, this chemosensor provides a novel approach for selectively recognition of Al(3+), Fe(3+) and Fe(2+) among environmentally relevant metal ions.

All-metal electride molecules CuAg@Ca7M (M = Be, Mg, and Ca) with multi-excess electrons and all-metal polyanions: molecular structures and bonding modes as well as large infrared nonlinear optical responses

All-metal electride molecules, CuAg@Ca₇M (M = Be, Mg and Ca), have been designed and researched in theory for the first time.