Detection Of Al3 Research Articles

Metal Ion‐Endows Orange‐Red Light Fluorogenicity of an Imine‐Linkage Probe Embracing Simple Electron Donor‐Acceptor Units

AbstractSelectively tracking and quantifying Al3+ ions is a significant concern to the scientific communities. In the present article, an imine‐linkage electron donor‐acceptor system, DSAN, (E)‐5‐(diethylamino)‐2‐(((2‐hydroxy‐4‐nitrophenyl)imino)methyl)phenol has been introduced which shows Al3+ ions endows red light fluorogenicity which could be utilized for sequential and detection of Al3+ ions and picric acid (PA) in both solid and liquid phases. Upon addition of Al3+ ions into the DSAN solution, an orange‐red fluorescence is noticed at 604 nm caused by the formation of Al3+ ions chelated DSAN complex having detection and quantification limit 0.2 μM and 0.62 μM respectively in dimethylformamide (DMF) medium. The complex formation is found to be a 1 : 1 stoichiometric ratio as evident from Job's plot analysis. Also, the binding affinity value is found to be 3.24×104 M−1 demonstrating a high affinity of DSAN towards Al3+ ions. This orange‐red fluorescence of Al3+ ions chelated DSAN complex solution is quenched due to the introduction of PA. A super handy paper‐strips‐based detection tool also been fabricated utilizing DSAN which could be employed to track trace amounts of Al3+ ions in the solid state. The mechanism involved in the detection of Al3+ ions is elucidated by density functional theoretical analysis.

A pyridine naphthalene conjugate: ESIPT based molecular chemosensor for Al3+ ions and sequential detection of H2PO4- and applications in milk, water samples and bio-imaging

A fluorescent probe (HL) with an "off-on-off" feature was created to identify Al3+ ions in aqueous solutions. The probe can identify Al3+ ions while other metal ions are present, and it is made to be straightforward to use. The probe was built utilizing a Schiff-base chemosensor, 1-[(pyridin-2-ylimino)] naphthalene-2-ol (HL), and a variety of spectroscopic methods were employed to describe it. Probe HL's sensing ability was assessed in a 1:1 volumetric ratio THF/H2O medium, and to establish the binding with Al3+ ions, several spectroscopic methods such as 1H NMR titration analysis, ESI-MS technique including DFT analysis were used. The probe HL showed notable alterations in fluorescence emission spectra during the detection of Al3+ and H2PO4- in the presence of other competing ions. The value of the association constant and the detection limit for Al3+ and H2PO4- were found to be 8.51×104 M-1 and 5.5×102 M-1, respectively. Besides, its applications as tests using milk and water samples successfully identified Al3+ ions in the presence of the probe HL. Additionally, probe HL was successfully examined in E.Coli pathogen for the sensing of Al3+ and H2PO4- ions

TPE[2]arenes: Luminescent macrocyclic arenes with aggregation-induced emission and Al3+ detection

Luminescent macrocyclic arenes have attracted interest owing to their unique cyclic geometry and adaptive emission. Herein, a series of fluorescent macrocyclic arenes, denoted as TPE [2]arenes, were easily synthesized by the one-pot condensation of tetraphenylethene (TPE) moiety and paraformaldehyde in the presence of BF3·OEt2 and readily derivatized to yield cyclic arenes with diverse substitution patterns. The macrocyclic arenes shared similar cyclic skeleton with resorcin [4]arene, and existed as two enantiomers with boat conformation confirmed via single crystal analysis. Furthermore, TPE [2]arenes all retained the aggregation-induced emission properties owing to the incorporation of TPE moiety and obvious mechanochromic luminescence behavior due to the relative flexible skeleton. The carboxylic acid substituted analogues, namely TPE [2]arene-COOH, exhibited specific “turn-on” detection of Al3+ ion in aqueous media.

Boron difluoride modified zinc metal-organic framework-based "off-on" fluorescence sensor for tetracycline and Al3+ detection.

A novel fluorescence "off-on" probe was developed using a boron difluoride-modified zinc metal-organic framework (Zn-MOF3) for sensitive determination of tetracycline (TC) and Al3+. The Zn-MOF3 has excellent optical property and good applicability in aqueous phase. The fluorescence recordedat 436nm was quenched at the excitation wavelength of 336nm. Signal-off detection of tetracycline via fluorescence quenching of Zn-MOF3 isbased on the inner filter effect. Fluorescence on-off-on detection of Al3+ occursvia the specific binding between tetracycline and Al3+. The limits of detection for TC and Al3+ were 28.4nM and 106.7nM, respectively. Thisprobe exhibited highselectivity which was used for the determination of TC and Al3+ with satisfied recoveries (89.8 to 105.6% for TC, 90.0 to 110.4% for Al3+) and good precision (< 5%) in milk. The developed sensor represents the first "off-on" system for fluorescence detection of TC and Al3+ based on Zn-MOF3 with a better aspect of the innovation.

A novel ethylene linkage-based covalent organic framework for turn-on fluorescence sensing for Al3+ with excellent selectivity and sensitivity

Covalent organic Framework (COFs) has become a new platform for functional research and material design. A novel covalent organic framework (CN-COF) was first synthesized with p-xylylene dicyanide and 2-hydroxy-1,3,5-benzenetrialdehyde through the Knoevenagel condensation reaction. CN-COF is a porous crystal material with strong thermal and chemical stability. CN-COF exhibits a selective “turn-on” fluorescence response to Al3+ in ethanol with blue-shifted emission spectra over the other tested metal ions. The color changes from pink to earth yellow, and the fluorescence effect is clearly visible. The fluorescence intensity of CN-COF was linearly related to the concentration of Al3+, and the detection limit was 1.815 μM. Importantly, CN-COF exhibits a satisfactory recovery for detecting Al3+ in drinking water and fish samples. CN-COF also showed the intuitive semi-quantitative detection ability for Al3+ via the color change with the naked eyes. The special pore structure is conducive to allow Al3+ enter to coordinate with O and N atoms on the wall of CN-COF scaffold. The revisable fluorescence change upon the selective addition of Al3+ and XRD, EDTA, XPS and DFT results demonstrated the complex process. The inhibition of the photoinduced electron transition from O atoms to Al3+ induced the fluorescence enhancement. This study not only presents a synthesis idea for a new structural organic framework, but also offers a highly selective and sensitive fluorescence chemical sensor for the identification and detection of Al3+.

Fluorescent MOF and Its Gel Composite for the Fluorescence Recovery "Turn-On" Detection of Al3+ Ions and "Turn-Off" Detection of Oxo-Anions.

The exploration of smart sensors is of great significance for the selectivity, sensitivity, and ability to show the low detection limit for the target analyte. Here, we have used the linker H2L (5-((anthracen-9-ylmethyl)amino)isophthalic acid) for the construction of {[Cd(L)(DMF)(H2O)2]·H2O}n (1) which is in order with the chromophore anthracene moiety and the free -NH functionality as a guest interaction site. This framework showed the luminescence recovery "turn-on" detection of the Al3+ ion in an aqueous solution. An exhaustive mechanism study disclosed that the Lewis acid-base-type interaction between the Al3+ ion and the -NH functionality of the linker in the framework revealed that the absorbance caused an enhancement for the "turn-on" sensing event. Besides the "turn-on" sensing event, the "turn-off" sensing phenomenon of 1 is also noticed when it detects the hazardous oxo-anions (MnO4- and CrO42-) with limit of detection values of 17.08 and 19.91 ppb, respectively. The detection of these diverse analytes are very fast (10 s) and they can also be recognized through a colorimetric response. The sensing mechanisms for these analytes are established by photoinduced electron transfer, Forster resonance energy transfer, and inert filter effect along with theoretical investigation. Furthermore, to show the sensing application of 1 in a versatile podium, a MOF gel composite, 1@AA (AA = Agar-Agar), was developed from 1 with AA. Interestingly, 1@AA showed the colorimetric detection of these analytes under UV light. Therefore, sensor 1 behaves as a smart sensory material for the recognition of the above analytes through a simultaneous "turn-on" and "turn-off" effect.

A tetraphenylethylene-based acylhydrazone Schiff base macrocycle exhibiting aggregation-induced emission and “turn-on” detection of Al3+ ions

A tetraphenylethylene-based acylhydrazone macrocycle (H8L) was designed and synthesized via Schiff base condensation reaction. The [2 + 2] molecular structure of H8L was determined via 1H NMR, 13C NMR, elemental analysis, ESI-MS, and single crystal X-ray diffraction. The “ESIPT + AIE” and selective recognition properties of macrocycle H8L were investigated via UV–vis absorption spectra and fluorescence emission spectra. The results showed that macrocycle H8L exhibited an obvious AIE characteristic in THF/H2O solution with varying water fraction, and displayed a selective “turn-on” response to Al3+ ions in the solution of THF/H2O (V: V = 4: 1). In addition, the visualization of latent fingerprints and the application of H8L on test strips were performed as well.

Ultrasensitive recognition performance of a folded π-based 1,8-naphthalimide-phthalocyanine fluorescence sensor

Designing ultrasensitive and smart molecules as molecular switches is highly valued in molecular recognition. In this work, a folded π-based molecular switch (NAPC) containing 1,8-naphthalimide and zinc(II) phthalocyanine functional modules was synthesized via cyclo tetramerization of four synthesized 1,8-naphthalimide sensors (NA). The photophysical properties of the folded molecular switch were investigated. This peripherally 1,8-naphthalimide substituted zinc(II) phthalocyanine possessed superior sensitivity in near-infrared “off-on” detection of Al3+, Fe3+, and Cr3+ compared with NA, and the detection limits were calculated to be 0.077 μmol/L for Al3+, 0.073 μmol/L for Fe3+ and 0.067 μmol/L for Cr3+, which were far less than that of NA. Due to the sensitive detection of Fe3+, NAPC was also applied in detecting NO2−. The ultrasensitive recognition mechanism of NAPC was determined to be the level-by-level linkage in the molecule in which the photo-induced electron transfer process in 1,8-naphthalimide sensor module was inhibited by complexing with metal ions first and then caused the inhibition of π-π stacking between two modules. This new folded molecule with a cascade linkage effect has the potential as an excellent fluorescence switch that could be applied in molecular recognition and environmental management.

Rhodamine B-Quinoline based schiff base as fluorescent ‘turn on’ sensor of Al3+, Cr3+, HSO4− and its cytotoxicity and cell imaging application on TPC-1 and HtH-7 cell lines

A designed Rhodamine-B-quinoline based Schiff base chemosensor (RhBQ) has been synthesized and characterized using various spectroscopic techniques. It shows ‘turn on’ fluorescence emission and also colorimetric sensitivity and selectivity towards trivalent metal ions (Al3+ and Cr3+) and anion (HSO4−) present in aqueous medium. Stoichiometry of both metal (Al3+ & Cr3+) - RhBQ complexes are found to be 1:1 using Job’s plot. A notable enhancement in emission intensity for RhBQ-Al3+ (∼341 fold), RhBQ-Cr3+ (∼292 fold), and RhBQ-HSO4− (∼136 fold) complexes compare to RhBQ are observed. Sensing mechanism i.e. opening of spirolactam ring of RhBQ has been confirmed through various spectroscopic techniques such as; 1H NMR, 13C NMR, ESI-MS, TRPL, FT-IR, and DFT based computational study. The limit of detection (LOD) for Al3+, Cr3+, and HSO4− are found to be 2.2 × 10−8 M, 2.12 × 10−8 M and 8.63 × 10−7 M respectively. An advanced level 3 input OR–INHIBIT logic gate are constructed using chelating ligand EDTA. For onsite detection, TLC paper strip spot of the probe, RhBQ is prepared and the detection of Al3+ in few antacid drug are presented. In addition, cell-imaging analysis of Al3+, Cr3+, and HSO4− ions in the Human papillary thyroid carcinoma cell line (TPC-1) & Human anaplastic thyroid cancer cell lines (HtH-7) are presented and shows promising concentration and time-dependent detection results.

Two novel Al3+ fluorescent-on probes based on thiazole substituted salicylaldehyde and its applications

ABSTRACT In this study, two structurally similar ‘turn on’ fluorescent probes B1 and B2 with high binding energy with Al3+ were synthesised. With new thiazole substituted salicylaldehyde fluorophore, these two hosts also have good selectivity and sensitivity in the detection of Al3+ based on the chelating fluorescence-enhancing effect under test conditions. They show an extremely low detection limit, 0.478 nM and 4.04 nM, respectively, with binding constants of 2.34 × 106 M−1 and 1.36 × 106 M−1. A 1:1 binding ratio of dual probes to Al3+ was demonstrated by working curves and mass spectrometry. The mechanisms were confirmed by 1H NMR and DFT calculations, defined that both two compounds combined with Al3+ by two oxygen atoms (one in C=O and another in -OH) and one nitrogen atom in -NH group to form triple coordination structure. Further application in test strips, actual soil and traditional Chinese medicine (TCM) suggest probes B1 and B2 have well application prospects in detecting Al3+.

A new quercetin@ZIF-8composite as turn-on fluorescent sensor for selective and sensitive detection of Al3+ ions

A fluorescent chemosensor (QCT@ZIF-8)based on ZIF-8 and quercetin was designed and synthesized.QCT@ZIF-8 retained the framework structure of ZIF-8 and also exhibited highly thermal and chemical stability. QCT@ZIF-8 started to decompose after 570 ℃ and its crystal structure remained unchanged after soaking in different solvents. QCT@ZIF-8 showed highly selective turn-on fluorescence response towards Al3+ in ethanol with very low detection limit. The fluorescence intensity of QCT@ZIF-8 increased linearly with the increase of Al3+concentration with the detection limit for Al3+ as low as 0.58 μM. The selective fluorescence response of QCT@ZIF-8 towards Al3+was attributed to the unique pore structure and chelating effect of quercetin with Al3+. The satisfactory recovery of QCT@ZIF-8 in detection of Al3+ in actual water samples proved that QCT@ZIF-8can be used as a fluorescent chemosensor for the identification and detection of Al3+ in environmental and water samples.

Discriminative 'Turn-on' Detection of Al3+ and Ga3+ Ions as Well as Aspartic Acid by Two Fluorescent Chemosensors.

In this work, two Schiff-base-based chemosensors L1 and L2 containing electron-rich quinoline and anthracene rings were designed. L1 is AIEE active in a MeOH-H2O solvent system while formed aggregates as confirmed by the DLS measurements and fluorescence lifetime studies. The chemosensor L1 was used for the sensitive, selective, and reversible 'turn-on' detection of Al3+ and Ga3+ ions as well as Aspartic Acid (Asp). Chemosensor L2, an isomer of L1, was able to selectively detect Ga3+ ion even in the presence of Al3+ ions and thus was able to discriminate between the two ions. The binding mode of chemosensors with analytes was substantiated through a combination of 1H NMR spectra, mass spectra, and DFT studies. The 'turn-on' nature of fluorescence sensing by the two chemosensors enabled the development of colorimetric detection, filter-paper-based test strips, and polystyrene film-based detection techniques.

A coumarin hydrazide Schiff base fluorescent probe for sensitively sensing Al3+ in living cells

A coumarin-based Schiff base fluorescence probe 1, which could specifically recognize Al3+ with high anti-interference was developed. After the addition of Al3+, the reaction reaches the platform in about 30 min with a fluorescent detection limit 0.12 μM. The coordination reaction between the carbonyl group, hydroxyl group, –NC- of probe 1 and Al3+ limits the molecular twist and fluorescence quenching effect from photoinduced electron transfer and then induces the increase of red fluorescence. The detection for Al3+ by the probe shows good repeatability in alternating Al3+ and EDTA. The probe was also applied to the successful monitoring Al3+ in living cells and real water sample.

Ratiometric Detection of Al Based on the Mixing of D‐penicillamine‐Functionalized Copper Nanoclusters with Pyridoxal 5’‐phosphate

AbstractThe excess accumulation of nonessential Al3+ in the human body can cause serious health problems, thus there is significant interest in the detection of Al3+. A new ratio fluorescent probe (RF‐probe) based on the mixing of red‐emitting D‐penicillamine (DPA) stabilized copper nanoclusters (DPA‐CuNCs) with pyridoxal 5’‐phosphate (PLP) was designed for sensitive and selective determination of Al3+. The −CHO group of PLP is expected to form an imine linkage with the free −NH2 group available of the DPA on the surface of DPA‐CuNCs. The content of Al3+ could be mensurated by the as‐prepared RF‐probe with a linear response in the range of 1.33–46.67 μmol ⋅ L−1, and corresponding limit of detection (LOD) was calculated to be 0.33 μmol ⋅ L−1. Moreover, the RF‐probe was successfully extended to the assay of Al3+ in aluminum carbonate chewing tablets, baking powder, pond water and drink water with satisfactory results compared to the standard atomic absorption spectroscopy (AAS).

Experimental and theoretical studies on naphthalene based fluorophores: Applications in detection of Al3+ ions in water, soil, food and live cells

Simple naphthalene based fluorescent chemosensors OHN &OHHN were prepared by single step procedures and utilized to detect Al3+ ion by absorption and emission spectroscopy. These studies confirmed that receptor OHHN showed significant selectivity and sensitivity towards Al3+ ion compared to other metal ions whereas there was no notable selectivity in the case of the receptor OHN. A significant enhancement in the fluorescence intensity was observed during the addition of Al3+ ions to the chemosensor OHHN. According to the emission studies, a plausible mechanism was proposed based on three reasons, i.e i) arrest of the Photoinduced Electron Transfer (PET), ii) CN isomerization and iii) Chelation Enhanced Fluorescence Effect (CHEF). The1H NMR and IR studies further confirmed the binding mechanism of the chemosensor OHHN with Al3+ ions. The fluorescence intensity changes in the Job’s plot predicts that the Al3+ ions bind with the receptor OHHN leading to the formation of a 1:2 stoichiometric ratio binding mode. The association constant and the limit of detection of the receptor OHHN with Al3+ ions were found to be 6.6×10−2M−1 and 0.176×10−5 M respectively. To test its real level effectiveness, the receptor OHHN has been tested with water, soil, food samples and live bacterial cell imaging.

A new NCDs@ZIF-90-based sensor: fluorescent "turn-on" detection of Al3+ ions with high selectivity and sensitivity.

A new NCDs@ZIF-90 composite as fluorescence sensor was designed and prepared by encapsulation of N-doped carbon dots (NCDs) in metal-organic framework (MOF) ZIF-90 in one-pot synthesis. NCDs@ZIF-90 retained the crystal structure and high thermal stability of ZIF-90; meanwhile, it also displayed the good chemical stability. NCDs@ZIF-90 dispersion in ethanol exhibited selective "turn-on" fluorescence response towards Al3+. The other coexisting competing metal ions had no obvious influence on the sensing performance of NCDs@ZIF-90 for Al3+. The fluorescence intensity at 447nm of NCDs@ZIF-90 dispersion in ethanol had good linear relation with the concentrations of Al3+ with a low detection limit of 3.196μM. The fluorescence enhancement after the addition of Al3+ was attributed to the release of NCDs from the inside of ZIF-90 to ethanol solution. In addition, NCDs@ZIF-90 displayed good recovery in detection of Al3+ in water samples indicating its practical application capability. The high selectivity and sensitivity indicate that NCDs@ZIF-90 is a good candidate as a "turn-on" fluorescence chemosensor to identify and detect Al3+.

A multi-responsive luminescent sensor based on a Cd(II) coordination polymer with turn-on sensing toward Al3+ and Cr3+ as well as ratiometric response to norfloxacin

Luminescent coordination polymers (CPs) can be as promising sensors in which an analyte-induced multi-responsive system with classy recyclability is conducive to the detection of plentiful deadly contaminants. A ternary Cd(II) CP, namely, [Cd(L)0.5(1,8-NDC)·H2O]n (1) (1,8-H2NDC = 1,8-naphthalenedicarboxylic acid) was constructed from the new flexibility 1,5-bis(thiabendazol-1-yl)pentane (L) and 1,8-H2NDC ligands under hydrothermal conditions. 1 possesses a 1D chain structure. 1 displays excellent pH resistance and luminescent sensing properties. 1 represents the first-ever CP for significant fluorescence “turn-on” detection of Al3+ and Cr3+ ions as well as ratiometric response to norfloxacin (NOR), even with the coexistence of other interferents. The luminescent sensing mechanism of 1 toward different analytes was discussed in detail.

Zn-MOF74 as a “turn-on” fluorescent chemosensor for recognition and detection of water in acetone and Al3+ in ethanol with high selectivity and sensitivity

Zn-based metal organic framework (Zn-MOF74) was prepared and well characterized. Zn-MOF74 is microporous crystalline framework and has high thermal and chemical stability. Zn-MOF74 displayed selective “turn-on” fluorescence enhancement response towards water in acetone and Al3+in ethanol. Water and Al3+ can induce the bright yellow-green and cyan fluorescence colors, respectively. The fluorescence intensity showed good linear relationship with water content in the range of 0–1.5% (volume percent) and with the concentration of Al3+ in the range of 0–200 μM, the detection limits were 0.045% for water and 0.61 μM for Al3+, respectively. In addition, Zn-MOF74 can be used to intuitively identify Al3+ by naked eyes in the form of test papers. Zn-MOF74 had good recovery of nearly 100% in the detection of Al3+ ions in practical water samples. The hydrogen bonding formation between H2O and O atom broke the coordination bonding between O atoms of hydroxyl on the MOF framework with Zn2+ ions, the electron distribution on MOF framework was changed and thus the fluorescence of MOF was obviously enhanced. The reversible fluorescence change, infrared spectra (IR) and x-ray photoelectron spectroscopy (XPS) demonstrated that fluorescence enhancement of Zn-MOF74 by Al3+ can be ascribed to the complex formation among them. Zn-MOF74 is a good candidate as “turn-on” fluorescence chemosensor for recognition and detection of water and Al3+ in different solvents.

A photoswitchable “turn-on” fluorescent chemosensor: Quinoline-naphthalene duo for nanomolar detection of aluminum and bisulfite ions and its multifarious applications

A quinoline-naphthalene duo-based Schiff base probe (R) was synthesized and characterized by the usual spectroscopic and single-crystal X-ray crystallographic techniques. Probe R detects Al3+ and HSO3− ions via the fluorescent turn-on approach by dual pathways i.e., i) when probe R interacts with Al3+, the restriction of CN single bond rotation, blocking of both photoinduced electron transfer (PET) and CN isomerization were observed, and ii) when the sensor R interacts with HSO3−, imine (CH = N) bond was cleaved via hydrolysis and produced the respective aldehyde and amine behaving as a chemodosimeter. The binding stoichiometric ratio of R + Al3+ (1:1) was confirmed by Job’s plot, emission titration profile, NMR, and mass spectrometric analyses. This probe R is highly selective to both Al3+ -ions and HSO3− -ions, without any interference of other potentially competing cations and anions. Limit of detection (LOD) and quantification (LOQ) of R with Al3+ and HSO3− were downed to nanomolar concentrations, which is much lower than the recommended level of drinking water/food fixed by the World Health Organization (WHO). Furthermore, probe R was utilized in the detection of Al3+ and HSO3− ions in highly contaminated real samples, bioimaging in E. coli cells, multiple-targeting molecular logic gate, and in bovine serum albumin (BSA) binding.

Tetraphenylethylene-based covalent organic frameworks as fluorescent chemosensor for rapid sensitive recognition and selective “turn-on” fluorescence detection of trace-level Al3+ ion

Abstract Tetraphenylethylene-based covalent organic framework (COF-DHTA) was prepared and then well characterized. COF-DHTA processes regular pore structure and high thermal stability. COF-DHTA suspension in DMF displays moderate fluorescence emission in DMF suspension and a highly selective fluorescence “turn-on” response towards Al3+ ions. The fluorescence intensity of COF-DHTA suspension at the emission peak 352 nm exhibits a good linear relationship with the concentration of the added Al3+ ions with a very low detection limit of 0.927 μmol/L. The selective and sensitive fluorescence enhancement recognition and detection for Al3+ ions can be attributed to the coordination of Al3+ ions with N and O atoms on the COF-DHTA and the suppression of photoinduced electron transfer (PET). The results of the N2 adsorption experiment, X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculation verified the coordination interaction between Al3+ ion and the N and O chelating sites on COF-DHTA. This work may pave the way to reasonable design fluorescent COF chemosensors for the recognition and detection of specific metal ions.