Synthesis and Application of 1,8-Naphthalimide Derivatives Fluorescent Probe for Sequential Recognition of Cu2+ and H2PO4. J Fluoresc 2024:10.1007/s10895-024-03692-y. [PMID: 38613712 DOI: 10.1007/s10895-024-03692-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

A naphthalimide Schiff base fluorescent probe (BSS) was designed and synthesized from 4-bromo-1,8-naphthalic anhydride, and its structure was characterized by 1HNMR, 13CNMR, FTIR, and MS. Fluorescence emission spectra showed that probe BSS could realize the "turn-off" detection of Cu2+ in acetonitrile solution, detection process with strong specificity and excellent anti-interference of other metal ions. In the fluorescence titration experiments, fluorescence intensity of BSS showed a good linear relationship with the Cu2+ concentration (0-10 µmol/L), and the detection limit was up to 7.0 × 10- 8 mol/L. Meanwhile, BSS and Cu2+ could form a 1:1 complex (BSS-Cu2+) during the reaction process. Under the same detection conditions, complex BSS-Cu2+ had specific fluorescence recovery properties for H2PO4- and the whole process was not only fast (6 s) but also free of interference from other anions, with a detection limit was as low as 5.7 × 10- 8 mol/L. In addition, complex BSS-Cu2+ could be successfully applied to the detection of H2PO4- in actual water samples, which with excellent application prospects.

Recent advances in the fluorimetric and colorimetric detection of cobalt ions

Cobalt is an essential metal to maintain several functions in the human body and is present in functional materials for numerous applications. Thus, to monitor these functions, it is necessary to develop suitable probes for the detection of cobalt. Presently, researchers are focused on designing different chemosensors for the qualitative and quantitative detection of the metal ions. Among the numerous methods devised for the identification of cobalt ions, colorimetric and fluorimetric techniques are considered the best choice due to their user-friendly nature, sensitivity, accuracy, linearity and robustness. In these techniques, the interaction of the analyte with the chemosensor leads to structural changes in the molecule, causing the emission and excitation intensities (bathochromic, hyperchromic, hypochromic, and hypsochromic) to change with a change in the concentration of the analyte. In this review, the recent advancements in the fluorimetric and colorimetric detection of cobalt ions are systematically summarized, and it is concluded that the development of chemosensors having distinctive colour changes when interacting with cobalt ions has been targeted for on-site detection. The chemosensors are grouped in various categories and their comparison and the discussion of computational studies will enable readers to have a quick overview and help in designing effective and efficient probes for the detection of cobalt in the field of chemo-sensing.

Highly sensitive and specific detection of Ni2+ using a novel fluorometric probe in the DMSO-H2O system

The rapid detection of Ni ions has important research and application value. This paper presents a novel specific turn-off fluorescence probe PCTMP-FS for detecting Ni2+ ions. The carbazole-based compound PCTMP is first synthesized via a two-step reaction. PCTMP-FS comprises PCTMP dispersed into a DMSO-H2O (fw = 30% v/v) mixed solvent. The probe demonstrates prominent selectivity and anti-interference abilities for detecting Ni2+ with a limit of detection (LOD) of 0.233 μM. The probe exhibits good applicability over a wide range of acidities. The detecting mechanism of the probe is due to the complex formed by PCTMP and Ni2+ (2:1), which destroys intramolecular charge transfer in the compound. The probe has good repeatability and demonstrates excellent stability and sensitivity for the detection of Ni2+ in real water samples.

Diethylaminophenol appended pyrimidine bis hydrazone for the sequential detection of Al3+ and PPi ions

In this study, a novel easy-to-prepare diethylaminophenol appended pyrimidine bis hydrazone (HD) has been designed and developed. The probe exhibits excellent sequential sensing characteristics towards Al3+ and PPi ions. The emission studies, various spectroscopic techniques and lifetime results have been utilized to understand the binding mechanism of HD with Al3+ ions and, to discover the specificity as well as the efficacy of the probe in sensing Al3+ ions. The good association constant in addition to the lower detection limit values makes the probe effective for the detection of Al3+. The in-situ produced HD-Al3+ ensemble could consecutively detect PPi via a turn-off fluorescence response and the selectivity and sensitivity characteristics of the generated ensemble towards PPi were described based on the demetallation approach. The overall sensing property of HD was perfectly employed for constructing logic gates, real water, and tablet applications. Paper strips, as well as cotton-swab experiments, were also conducted inorder to check the practical utility of the synthesized probe.

A facile chemiluminescence strategy for copper(ii) ion detection utilizing azothiacalix[4]arene-functionalized carboxymethylcellulose polymeric ligand

The design and characterization of azothiacalix[4]arene-functionalized carboxymethylcellulose, used for the detection of nanomolar levels of Cu2+via a chemiluminescence method.

A Comprehensive Review on Thiophene Based Chemosensors

The recognition and sensing of various analytes in aqueous and biological systems by using fluorometric or colorimetric chemosensors possessing high selectivity and sensitivity, low cost has gained enormous attention. Furthermore, thiophene derivatives possess exceptional photophysical properties compared to other heterocycles, and therefore they can be employed in chemosensors for analyte detection. In this review, we have tried to explore the design and detection mechanism of various thiophene-based probes, practical applicability, and their advanced models (design guides), which could be thoughtful for the synthesis of new thiophene-based probes. This review provides an insight into the reported chemosensors (2008-2020) for thiophene scaffold as effective emission and absorption-based chemosensors.

[Determination of cyanogen chloride in organic and water matrices by gas chromatography-mass spectrometry based on thiol derivatization]

Cyanogen chloride (ClCN) has been widely used in industrial production. ClCN is also listed in the Schedule of the Chemical Weapons Convention (CWC). The use of traditional colorimetric analysis or gas chromatography for the detection of ClCN has been characterized by low efficiency and poor sensitivity. In this study, a method was established for the qualitative analysis and quantitative detection of ClCN in organic and water matrices by gas chromatography-mass spectrometry (GC-MS) based on thiol derivatization. 1-Butylthiol was selected as the optimal derivatization reagent. The optimal temperature for thiol derivatization in the organic matrices was 40 ℃ and the reaction time was 10 min. The pH for derivatization was approximately 9. The ClCN in the organic matrices was directly analyzed by GC-MS after derivatization. The conditions of ClCN derivatization in the water matrices were the same as those in the organic matrices. After the derivatization of ClCN, headspace-solid phase microextraction (HS-SPME) was employed during sample preparation for water matrices. Different temperatures for HS-SPME were explored, and the optimal temperature was found to be 55 ℃. The product of thiol derivatization was confirmed as butyl thiocyanate. The main fragmentation patterns and mass spectrometric cleavage pathway were investigated by GC-MS/MS. The quantitative determination of ClCN in organic and water matrices was conducted via the internal standard and external standard methods, respectively. ClCN showed good linearity in the corresponding ranges in the organic and water matrices. The correlation coefficients for both matrices were greater than 0.99. The linearities of ClCN in the organic and water matrices were in the range of 20-2000 μg/L and 20-1200 μg/L, respectively. An organic sample and water samples from different substrates were selected to verify the accuracy and precision of the method at three spiked levels. The average spiked recoveries of ClCN in the organic sample and water samples were 87.3%-98.8% and 97.6%-102.2%, respectively. The corresponding relative standard deviations (RSDs, n=6) were 2.1%-4.7% and 2.8%-4.2%. The derivatization method established in this study showed good reaction specificity. The method was successfully applied in the analysis of samples obtained from the Organisation for the Prohibition of Chemical Weapons (OPCW). The method established in this study for the detection of ClCN showed high sensitivity and precision, and could aid in the analysis and detection of ClCN in the environment.

A label-free fluorescent peptide probe for sensitive and selective determination of copper and sulfide ions in aqueous systems

A label free fluorescent peptide probe (HDSGWEVHH) was used for Cu2+ and S2- determination in aqueous solution. Our results demonstrated that HDSGWEVHH is highly selective and sensitive for monitoring free Cu2+ concentration via quenching of the probe fluorescence upon Cu2+ binding. The mechanism of the complexation is investigated with Cyclic Voltammetry (CV), 1H nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) spectroscopy and computational techniques. Theoretical calculation results indicated the binding ratio of the probe to Cu2+ is 2 : 1 and the binding constant was obtained as 1.72 × 10 8 M-1. Cu2+ concentration can be detected with the detection limit of 16 nM. Free Cu2+ concentration released from the metallothionein-Cu complex at different pH values was detected. Cu2+ concentration in real water and tea samples was also detected, and the results were consistent with the ones monitored by atomic absorption spectrometer. Because of the exceedingly small K sp value of CuS (1.27 × 10-36), S2- can sequester Cu2+ from HDSGWEVHH to restore the tryptophan (W) fluorescence. Thus the HDSGWEVHH-Cu2+ complex can also be used for S2- detection. The S2- concentrations can be monitored with a detection limit of 19 nM. The assay is also amenable to measurement of S2- concentration in pure water samples. Thus the probe designed herein is sensitive, label free, low cost, and environmentally friendly for Cu2+ and S2- determination in aqueous solutions.

A dual-functional fluorescent probe for sequential determination of Cu2+/S2- and its applications in biological systems

A new acylhydrazine-derived Schiff base fluorescence probe DMI based on "ON-OFF-ON" fluorescence strategy was presented in this paper. Probe DMI could detect Cu²⁺ selectively and sensitively with dramatic fluorescence quenching in CH₃OH-PBS (v/v = 3:7) mixed solution. Once the complex DMI-Cu²⁺ interacted with S^2-, 10.67-folds fluorescence increase was induced via a displacement mechanism under the same experimental conditions. The corresponding detection limits for Cu²⁺ and S^2- were calculated to be 1.52 × 10^-8 M and 1.79 × 10^-8 M, respectively. The structures of DMI and DMI-Cu²⁺ were systematically characterized by Job's plot analysis, ESI-MS, IR, X-ray diffraction and density functional theory calculations. Furthermore, fluorescence imaging in MCF-7 cells and zebrafish demonstrated the probe DMI could act as a useful tool to monitor and track intracellular Cu²⁺ and S^2-, which was encouraged by remarkable fluorescence performance and low cytotoxicity. Importantly, the complex DMI-Cu²⁺ could be applied to detect corrupt blood samples, which could estimate the time of death.

TICT fluorescent probe for Al3+: Sequential detection of PPi, ATP and ADP in semi-aqueous medium and real-life applications

A ditopic Schiff base ligand, H₂L has been synthesized and characterized by all spectroscopic techniques. It is highly selective and specific towards Al³⁺ in semi aqueous medium (DMF/H₂O mixture) by exhibiting a drastic increase in the fluorescence intensity. The emission studies, spectroscopic data, life time and quantum yield results have been used to understand its binding mode, explore its specificity and establish its efficacy. The intensity difference is remarkable in physiological pH range. Due to its reversible behavior this ditopic fluorescent chemosensor can be used multiple times to make it cost effective. Detection limit for this chemosensor was found to be 0.65 μM. Experiments with TLC plates show that it can be used as a practical and portable sensor for studying environmental samples in real life. The L-Al³⁺ complex generated in the solution acts as a sensor to sequentially detect pyrophosphate groups present in inorganic pyrophosphates, ATP and ADP among other anions by turning off the fluorescence. Inhibit logic gate and its corresponding truth table has been developed to aid in further exploiting its multidimensional applications.

Construction of Chiral "Triple-Decker" Nd(III) Nanocluster with High NIR Luminescence Sensitivity toward Co(II)

One Nd(III) complex [Nd₃L₃(OAc)₃] (1) was synthesized from a conjugate Schiff base ligand H₂L. It shows a chiral "triple-decker" structure (1.1 × 1.2 × 1.8 nm) with Nd(III) ions sandwiched between the Schiff base ligands. 1 exhibits NIR Nd(III) luminescence, and the LMET efficiency is calculated to be 13.8%. It displays high luminescence sensitivity and selectivity to Co(II). The K_SV value and LOD of 1 to Co(II) are 9.96 × 10⁴ M^-1 and 0.97 μM, respectively.

A highly selective colorimetric and fluorescent probe for quantitative detection of Cu2+/Co2+: The unique ON-OFF-ON fluorimetric detection strategy and applications in living cells/zebrafish

Identifying and detecting similar target cations through combining "turn on" and "turn off" fluorescence mechanism is effective and challenging. Now a new colorimetric and ON-OFF-ON fluorescent probe N'-((7-(diethylamino)-2-oxo-2H-chromen-3-yl)methylene)-3-hydroxy-2-naphthohydrazide (L) was reported, which could detect Cu²⁺ and Co²⁺ in phosphate buffered CH₃CH₂OH-H₂O solvent system. With the assistance of glutathione and pH adjustment, a unique ON-OFF-ON fluorescence detection strategy could be achieved for distinguishing Cu²⁺ and Co²⁺. The emission of probe could recover from the L-Cu²⁺ and L-Co²⁺ system by addition of GSH or adjusting pH value to 4, respectively, which is due to the abolishment of paramagnetic Cu²⁺/Co²⁺. Based on fluorescence titration experiments, the limit of detection was determined as 3.84 × 10^-9 M and 4.55 × 10^-9 M for Cu²⁺ and Co²⁺, respectively. Meanwhile, the detection limit reached 6.21 × 10^-8 M for Cu²⁺ and 6.96 × 10^-8 M for Co²⁺ according to absorbance signal output. Fast recognition of Cu²⁺/Co²⁺ can be achieved by obvious color changes from green to colorless under UV light, as well as from yellow to orange-red in room light. The binding mode of L toward Cu²⁺ and Co²⁺ have been systematically studied by Job's plot analysis, ESI-MS, IR and density functional theory calculations. Most strikingly, further practical applications of the probe L in fluorescence imaging were investigated in MCF-7 cells and zebrafish due to its low cytotoxicity and good optical properties, suggesting that L could serve as a fluorescent sensor for tracking Cu²⁺ and Co²⁺in vivo.

A nano-molar level fluorogenic and oxidation state-selective chromogenic dual reversible chemosensor for multiple targets, Cu2+/S2− and Fe3+/F− ions

A pyridine–pyrazole–pyrene-based multipurpose chemosensor has been introduced which has been found to exhibit excellent luminescent and optical properties.

A dual-responsive colorimetric probe for the detection of Cu2+ and Ni2+ species in real water samples and human serum

The monitoring of heavy transition metals has increasingly attracted great attention because they pollute the environment and have unique physiological functions. Chemosensors are useful tools for monitoring heavy transition metals due to their simple visualization, excellent sensitivity and high selectivity. Herein, we have developed a novel chemosensor for the detection of water-soluble Cu2+ and Ni2+ species with different mechanisms, and low detection limits of 2.1 nM for Cu2+ and 1.2 nM for Ni2+ were obtained. The colorimetric probe CPH has been applied to qualitative and quantitative detection of Cu2+ and Ni2+ species in real samples.

Triazole-based novel bis Schiff base colorimetric and fluorescent turn-on dual chemosensor for Cu2+ and Pb2+: application to living cell imaging and molecular logic gates

A triazole-based novel bis Schiff base colorimetric and fluorescent chemosensor (L) has been designed, synthesized and characterized by elemental analysis, ¹H-NMR, ESI-MS, FTIR spectra and DFT studies. The receptor L showed selective and sensitive colorimetric sensing ability for Cu²⁺ and Pb²⁺ ions by changing color from colorless to yellow and light yellow respectively in CH₃OH–tris-buffer (1 : 1, v/v). However, it displayed strong fluorescence enhancement upon the addition of both Cu²⁺ and Pb²⁺ ions, attributed to the blocking of PET. The fluorometric detection limits for Cu²⁺ and Pb²⁺ were found to be 12 × 10⁻⁷ M and 9 × 10⁻⁷ M and the colorimetric detection limits were 3.7 × 10⁻⁶ M and 1.2 × 10⁻⁶ M respectively; which are far below the permissible concentration in drinking water determined by WHO. Moreover, it was found that chemosensor L worked as a reversible fluorescence probe towards Cu²⁺ and Pb²⁺ ions by the accumulation of S²⁻ and EDTA respectively. Based on the physicochemical and analytical methods like ESI-mass spectrometry, Job plot, FT-IR, ¹H-NMR spectra and DFT studies the detection mechanism may be explained as metal coordination, photoinduced electron transfer (PET) as well as an internal charge transfer (ICT) process. The sensor could work in a pH span of 4.0–12.0. The chemosensor L shows its application potential in the detection of Cu²⁺ and Pb²⁺ in real samples, living cells and building of molecular logic gate.

A novel triazole-based bis Schiff base colorimetric and fluorescent chemosensor (L) has been designed, synthesized and characterized. The chemo-sensor L shows its application potential in the detection of Cu²⁺ and Pb²⁺ in living cells and building molecular logic gate.

A new Schiff-base chemosensor for selective detection of Cu2+ and Co2+ and its copper complex for colorimetric sensing of S2- in aqueous solution

A new Schiff-base colorimetric chemosensor 1 was developed for the detection of Cu²⁺, Co²⁺ and S^2-. Sensor 1 could simply monitor Cu²⁺ and Co²⁺ by a color change from colorless to yellow. The binding modes of 1 to Cu²⁺ and Co²⁺ were determined to be a 2 : 1 complexation stoichiometry through Job's plot and ESI-mass spectrometry analysis. The detection limits (0.02 μM and 0.63 μM) for Cu²⁺ and Co²⁺ were lower than the recommended values (31.5 μM and 1.7 μM) by the World Health Organization (WHO) for Cu²⁺ and the Environmental Protection Agency (EPA) for Co²⁺, respectively. Importantly, 1 could detect and quantify Cu²⁺ in real water samples. In addition, the Cu²⁺-2·1 complex could be used as a highly selective colorimetric sensor for S^2- in the presence of other anions without any interference. Moreover, the sensing mechanisms of Cu²⁺ and Co²⁺ by 1 were explained by theoretical calculations.

A highly sensitive pyridine-dicarbohydrazide based chemosensor for colorimetric recognition of Cu2+, AMP2−, F− and AcO− ions

A single colorimetric chemosensor for the detection of both Cu²⁺ and AMP²⁻ ions has been developed for the first time.

Single fluorescent chemosensor for multiple targets: sequential detection of Al3+ and pyrophosphate and selective detection of F− in near-perfect aqueous solution

An easily fabricated chemosensor was developed for selective fluorescence detection of three analytes, Al³⁺, pyrophosphate (PPi), and F⁻, in aqueous solution.