Detection Of Nitrobenzene Research Articles

Preparation of copper and phosphorus co-doped three-dimensional layered hexagonal cobalt nanodisks for monitoring nitrobenzene in environmental pollutants

In this study, copper and phosphorus co-doped three-dimensional layered hexagonal cobalt nanodiscs were synthesized using a rapid and simple method and were applied for the detection of nitrobenzene, an environmental pollutant. The incorporation of phosphorus into the nanodiscs created catalytic sites, while the addition of copper increased the density of active sites and facilitated rapid charge transfer. Co-doping phosphorus and copper allowed the CuCo NDs/P composite material to exhibit excellent catalytic activity towards nitrobenzene. Experimental results demonstrated that CuCo NDs/P had a lower detection limit and a broader linear range. Additionally, the sensor was tested on natural water samples to evaluate its practical feasibility, indicating significant potential for further development.

Two three-dimensional coordination polymers as fluorescence probes for the detection of nitrobenzene, tetracycline, fluazinam and their application in green pepper

Two coordination polymers (CPs), [Zn5(L)2(phen)5](1) and [Cd2(HL)(2,2-bpy)(H2O)3](2), were synthesized by using 2′,3,3′,5,5′-Diphenyl ether pentacarboxylic acid (H5L), phenanthroline (phen), and 2,2′-bipyridine (2,2′-bpy) under hydrothermal conditions. The L5- ligand adopts the μ6-к2: к2: к1: к1: к1: к1 mode in 1 and the μ5-к2: к2: к2: к2: к1 mode in 2. Sensing experiments show that 1 and 2 are fluorescence probes with high sensitivity and rapid detection of nitro explosives, antibiotics, and pesticides. In order to verify the ability of 2 to detect FLU in actual samples, we performed a spiked recovery experiment in green pepper water. The spiked recoveries were 97.77–101.18 %. Interestingly, because H5L is not completely deprotonated in 2, there is abundant hydrogen bonding, which makes the fluorescence quenching rate higher and the detection limit lower. The possible fluorescence quenching mechanism of 1 and 2 can be explained by their UV–VIS absorption spectra and orbital energy levels.

Quenching and enhancement mechanisms of a novel Cd-based coordination polymer as a multiresponsive fluorescent sensor for nitrobenzene and aniline

BackgroundNitroaromatic compounds are inherently hazardous and explosive, so convenient and rapid detection strategies are needed for the sake of human health and the environment. There is an urgent demand for chemical sensing materials that offer high sensitivity, operational simplicity, and recognizability to effectively monitor nitroaromatic residues in industrial wastewater. Despite its importance, the mechanisms underlying fluorescence quenching or enhancement in fluorescent sensing materials have not been extensively researched. The design and synthesis of multiresponsive fluorescent sensing materials have been a great challenge until now. ResultsIn this study, a one-dimensional Cd-based fluorescent porous coordination polymer (Cd–CIP-1) was synthesized using 5-(4-cyanobenzyl)isophthalic acid (5-H2CIP) and 4,4′-bis(1-imidazolyl)biphenyl (4,4′-bimp) and used for the selective detection of nitrobenzene in aqueous solution by fluorescence quenching, with a limit of detection of 1.38 × 10−8 mol L−1. The presence of aniline in the Cd–CIP-1 solution leads to the enhancement of fluorescence property. Density functional theory and time-dependent density functional theory calculations were carried out to elucidate the mechanisms of the fluorescence changes. This study revealed that the specific pore size of Cd–CIP-1 facilitates analyte screening and enhances host-guest electron coupling. Furthermore, π–π interactions and hydrogen bond between Cd–CIP-1 and the analytes result in intermolecular orbital overlap and thereby boosting electron transfer efficiency. The different electron flow directions in NB@Cd–CIP-1 and ANI@Cd–CIP-1 lead to fluorescence quenching and enhancement. Significance and noveltyThe multiresponsive coordination polymer (Cd–CIP-1) can selectively detect nitrobenzene and recognize aniline in aqueous solutions. The mechanism of fluorescence quenching and enhancement has been thoroughly elucidated through a combination of density functional theory and experimental approaches. This study presents a promising strategy for the practical implementation of a multiresponsive fluorescent chemical sensor.

Utilizing excited-state proton transfer fluorescence quenching mechanism, layered rare earth hydroxides enable ultra-sensitive detection of nitroaromatic

Convenient, rapid, and accurate detection of nitroaromatic organic toxins and harmful substances is of great significance in research. In the present study, two-dimensional layered rare-earth hydroxides (LYH) were used as ion-exchange matrix materials, and the anionic fluorescent dye molecules (HPTS) were successfully introduced into the LYH structures in situ via a simple and effective “plug-and-play” strategy, which gave the compounds ultra-sensitive fluorescence sensing detection of nitrobenzene, p-nitrotoluene and p-nitrophenol (Fluorescence response time < 1 sec, and the LOD for nitrobenzene, p-nitrophenol and p-nitrotoluene reached an impressive 349 ppb, 22 ppb and 98 ppb, respectively). Combined with theoretical calculations, we elucidated in detail the fluorescence quenching response mechanism of the LYH-HPTS towards nitroaromatic. Additionally, we also constructed fluorescent paper sensor, which effectively transformed the LYH-HPTS from theoretical detection to device application. The LYH-HPTS material is not only simple to synthesize, cost-effective and stable, but also has the features of fast response, excellent sensitivity and selectivity, and good reproducibility, which provides a new approach for the rapid and accurate detection of nitroaromatic.

Efficient nanostructured Cs2CuBr2Cl2 perovskite as a fluorescent sensor for the selective “Switch Off” detection of nitrobenzene

Lead halide nanostructured perovskites are well known for their excellent photoluminescence and optoelectronic properties. However, lead toxicity and instability in moisture impedes its suitability for material use. Here we synthesized a highly efficient, lead free, economical, stable Cs2CuBr2Cl2 perovskite nanocrystals (PNCs) via Ligand Assisted Re-Precipitation (LARP) method which is less explored. The sensing application of the synthesized PNCs towards nitro explosives and other small organic compounds were studied. The probe exhibited high selectivity towards nitrobenzene with a lowest detection limit of 57.64 nM. The fluorescent emission intensity was drastically quenched upon the addition of 32 µM nitrobenzene. A Stern-Volmer plot was utilized for the quantification of fluorescence quenching. Further to investigate the quenching mechanism, time correlated single photon counting spectroscopy and other photoluminescence studies were performed pointing out the possibility of fluorescence resonance energy transfer. The work has been further extended to test the capability of the probe to detect nitrobenzene in real water samples and a good recovery percentage ranging from 93-98 % was obtained. Further, a paper strip assay was designed which successfully detected nitrobenzene and can be clearly noticed even with our naked eye making the probe an excellent sensor for nitrobenzene detection.

Lithium‐Lanthanide Heterometallic Organic Frameworks with Near‐Unity Photoluminescence Quantum Yields for Single‐Composition White‐Light Emission and Fluorescent Sensing on Nitrobenzene

AbstractLanthanide ion contained metal–organic frameworks (MOFs) have garnered significant attention in the fields of solid‐state lighting and chemical sensing due to their porous structure and distinctive optical properties. However, they also present challenges because of the limited photoluminescence (PL) intensity resulting from the parity‐forbidden f–f transitions of lanthanide ions. Herein, the study reports a new heterometallic MOFs Ln3Li2L4 (Li‐Ln‐MOF, Ln = Y, Eu, Tb and Dy, L = deprotonated 1,3,5‐tris(4‐carboxyphenyl)benzene) with a Brunauer‐Emmett‐Teller (BET) surface area of 774.1 m2/g. The porous crystal structure of Li‐Ln‐MOF is characterized by three kinds of channels interpenetrating with each other. By employing ligand alternation and lanthanide ion alloying strategies, Li‐Y1‐xEux‐MOF1 crystal isostructural with Li‐Ln‐MOF is synthesized by using 2,4,6‐tris(4‐carboxyphenyl)‐1,3,5‐triazine (H3TATB) as ligand. The Li‐Y0.7Eu0.3‐MOF1 crystal excels in the comprehensive performance with a BET surface area of 858.8 m2 g−1 and a near‐unity PL quantum yield. The time density functional theory and natural transition orbitals calculations unravel that the outstanding optical properties Li‐Y0.7Eu0.3‐MOF1 originates from the charge transfer between TATB3− and Eu3+. Benefiting from the excellent comprehensive performance of Li‐Y1‐xEux‐MOF1, the study reveals their potentials as single‐composition white‐light emission and fluorescent sensing probe for the detection of nitrobenzene.

Highly sensitive fluorescent nitrobenzene gas sensing by nitrogen-doped graphene quantum dots embedded in ZIF-8 nanocomposite

This study introduces a straightforward and highly sensitive luminescence gas sensor designed for the detection of nitrobenzene in gaseous state. The sensor utilizes an innovative composite composed of nitrogen doped graphene quantum dots (nGQDs) as luminescent materials, successfully encapsulated within the stable porous carrier zeolitic imidazolate framework-8 (ZIF-8). The resulting nGQD@ZIF-8 nanocomposite showed highly sensitive luminescence sensing towards nitrobenzene gas, with a wide linear detection range from 8 to 320 ppm, and the detection limits of sensor as low as 0.44 ppm. Moreover, the nGQD@ZIF-8 sensor demonstrated enhanced ppm-level sensitivity and long-term stability for nitrobenzene detection at room temperature, while maintaining high stability under varying humidity levels and exposure to high temperatures. This enhancement is attributed to the increased contact area provided by ZIF-8 matrix, facilitating adsorption of nitrobenzene molecules on nGQDs. The nGQD@ZIF-8 exhibited good selectivity towards nitrobenzene gas (57 %) compared to other nitro volatile organic compound (VOC) vapors (nitromethane and nitropropane), and almost no significant responses were observed for the other tested VOC vapors (methanol, acetone, formaldehyde, benzene). This can be attributed to the strong interaction between the electron-deficient nitrobenzene and the nGQD@ZIF-8 nanocomposite. Overall, the proposed gas sensor in this study showed high potential for a simple, efficient, and reliable detection of nitrobenzene gas in environmental monitoring.

Preparation of Ni, Co doped hollow carbon nanocage from core-shell structure ZIF-8@ZIF-67 for nitrobenzene monitoring

Herein, we employed a Ni, Co duplex metal-doped hollow carbon nanocage derived from the core-shell Zeolite imidazole framework-8 (Zn)@Zeolite imidazole framework-67 (Co) (ZIF-8@ZIF-67) for the sensitive electrochemical detection of nitrobenzene (NB). The precursor was created by coating ZIF-67 on the surface of ZIF-8 through the epitaxial growth method, followed by Ni doping. Subsequent pyrolysis resulted in the formation of a Ni, Co duplex metal-doped hollow carbon nanocage. Characterization of the nanocomposite confirmed the unique hollow and porous structure of NiCo/C, maintaining a dodecahedral morphology with a uniform distribution of carbon and transition metal nanoparticles. The NiCo/C-modified electrode exhibits a wide linear dynamic range (0.05–11.22 μM and 11.22–230.06 μM), a lower limit of detection (0.14 μM), superior stability and selectivity for the detection of NB. Moreover, it shows appropriate practicality toward detecting NB in natural water samples.

Extensive optical and DFT studies on novel AIE active fluorescent sensor for Colorimetric and fluorometric detection of nitrobenzene in Solid, solution and vapor phase

An electron rich isophthalamide based sensor IPA has been synthesized through a simple two-step reaction, containing noteworthy aggregation induced emission (AIE) properties. Considering the significant emission with λmax at 438 nm, sensor IPA has been employed for the sensing of nitrobenzene (NB) in solid, solution and vapor state with high sensitivity and selectivity. Sensor IPA showed noteworthy colorimetric and fluorometric quenching in fluorescence emission when exposed to NB. Small size of NB and involvement of photoinduced electron transfer (PET) lead to detection of NB down to 60 nM. IPA-NB interaction was studied through UV–Vis. spectroscopic studies along with fluorescence spectroscopy. Moreover, 1H and 13C NMR titration experiments provided additional support for determination of interaction type. Furthermore, by using density functional theory (DFT) calculations, thermodynamic stability was studied. Additionally, non-covalent interactions (NCI), frontier molecular orbitals (FMO), density of states (DOS), were investigated for providing further evidence of nitrobenzene sensing and its interaction with sensor. Natural bond orbital (NBO) analysis was carried out for charge transfer studies. Quantum theory of atom in molecule (QTAIM) and SAPT0 studies provided information about interaction points and binding energy. Additionally, IPA was investigated for NB sensing in real water samples, and its effective participation in solid state on-site detection as well as in solution phase was brought to light along with logic gate construction.

Retraction Note: Zn(II)-Containing Metal–Organic Framework for Fluorescence Detection of Nitrobenzene and Prevention Effect on Hypertension via Down-Regulating the Expression of Vitamin D Receptor

Retraction Note: Zn(II)-Containing Metal–Organic Framework for Fluorescence Detection of Nitrobenzene and Prevention Effect on Hypertension via Down-Regulating the Expression of Vitamin D Receptor

A new Eu(III)-based metal-organic framework: synthesis, characterization, fluorescence detection of nitrobenzene and catalytic conversion of CO2

The employment of metal-organic frameworks (MOFs) as fluorescence sensors for the detection of environmental pollutants and/or heterogeneous catalysts for CO2 conversion is of great importance for protecting human health. For this purpose, we synthesized a new Eu-MOF [Eu2(btpdc)2·(HCOO)2]n (1) (H2btpdc = benzo[b]thiophene-2,5-dicarboxylic acid) with its three-dimensional structure characterized by single-crystal X-ray diffraction. The powder X-ray diffraction (PXRD) and thermal gravimetric analysis (TGA) results indicate that 1 has high chemical durability, good water stability and high thermal stability. Fluorescence sensing investigations demonstrate that 1 is a smart chemical sensor towards nitrobenzene (NB) detection with high sensitivity, high selectivity and good regeneration performance. A high quenching constant (Ksv = 2.33 × 105 M−1) and a low detection limit (LOD = 0.038 μM) are obtained. Combined with experiments and density functional theory calculations, the mechanisms of fluorescence quenching of 1 by NB were also revealed. Furthermore, 1 can serve as a smart catalyst for the cycloaddition reaction of CO2 with epoxides to synthesize cyclic carbonates, displaying high activity, high selectivity, and good generality.

Assembly of three new triphenylamine functionalized MOFs for the fluorescent sensing of nitrobenzene

The detection of nitrobenzene (NB) is very important because it has a series of irreversible effects on human health. Metal-organic frameworks (MOFs) show potential applications in this field due to their tunable and porous structures. In this work, three new MOFs, namely [Mn3(TCA)2(DMF)4]·DMF (JOU-28), [Cd21(TCA)14(H2O)9]·21DMF·21H2O (JOU-29), and [Cd3Cl3(TCA)(DMF)2]·H2O (JOU-30), were successfully prepared by solvothermal method (H3TCA = 4,4′,4″-tricarboxytriphenylamine; DMF = N,N′-Dimethylformamide). Single crystal X-ray diffractions showed that JOU-28 was a 3D porous supramolecular structure based on 2D coordination networks, while both JOU-29 and JOU-30 were 3D porous structures based on 1D chains. Due to its strong fluorescence emission, JOU-29 was selected as a representative to study the NB sensing performance. A linear relationship between the NB concentration and the fluorescence emission intensity of JOU-29 could be obtained as I0/I = 0.952 + 8089[NB]. This result showed that JOU-29 can be used for quantitative detection of NB. Further studies revealed that the fluorescence quenching of JOU-29 may be due to the fluorescence resonance transfer effect and the competitive absorption. This work provides clues for the design and synthesis of fluorescent MOFs for NB detection.

1D + 3D → 3D zinc polyrotaxane MOF: Selective fluorescent detection of nitrobenzene, uric acid and sucrose and photocatalytic degradation of Rose Bengal and Congo Red dyes

A new Zn based polyrotaxane 3D metal-organic framework (MOF), {[Zn3(BTC)2(Bimb)3.5][Zn(HCOO)(Bimb)1.5]·CH3COO·2(CH3)2NH·2DMF·9H2O}n (KA@MOF-S2)(Bimb = 1,4-bis[(1H-imidazol-1-yl)methyl]benzene, BTC3‒ = 1,3,5-benzenzetricarboxylate) has been synthesized under solvothermal conditions. Single-crystal X-ray diffraction analysis reveals that KA@MOF-S2 exhibits a novel 1D + 3D → 3D interpenetratedPolyrotaxane MOF architecture. KA@MOF-S2 possesses a new 3,3,3-c net 3-nodal interpenetrated network with (122.14)(8.122)(83)2 topology. KA@MOF-S2 can be used as a selective fluorescence sensing material for the quantitative detection of VOCs (Acetone, NB), antibiotic (NFT) and biomolecules (UA, sucrose) and photocatalytic degradation of Rose Bengal (RB) and Congo Red (CR) dye under sun-light irradiation.

Fluorescence-quenching mechanisms of novel isomorphic Zn/Cd coordination polymers for selective nitrobenzene detection

Nitroaromatic compounds in aqueous undermine environmental sustainability and affect human health. The development of a fluorescent sensor capable of efficiently and selectively detecting trace amounts of nitroaromatic compounds presents a considerable challenge. This study introduced Zn/Cd isomeric coordination polymers (Zn-H2CIA-1/Cd-H2CIA-2), which are synthesized using 5-((4-carboxybenzyl)oxy)isophthalic acid (5-H3CIA) and 1,10-phenanthroline (Phen). The polymers have zero-dimensional discrete crystal structure with a six-coordinated scissor-like shape. The two coordination polymers can be used as fluorescent sensors for detecting nitrobenzene (NB) and demonstrated favorable sensitivity, with detection limits of 1.95 × 10−8 and 4.66 × 10−7 mol/L, respectively. Zn-H2CIA-1 exhibited stronger fluorescence and a more sensitive response to NB compared with Cd-H2CIA-2. To elucidate their fluorescence-quenching mechanisms, we analyzed Zn-H2CIA-1 by performing DFT and TD-DFT calculations. The pore structure, density of states, excitation energy, hole–electron distribution, and orbital composition were analyzed. The suitable size of pores in Zn-H2CIA-1 is the main reason for its high NB selectivity. Moreover, intermolecular π-π stacking interactions result in an orbital overlap between Zn-H2CIA-1 and NB, enabling the transfer of electrons from Zn-H2CIA-1 to NB. This electron transfer is identified as the fundamental cause of fluorescence quenching in Zn-H2CIA-1.

An extensive experimental and DFT studies on highly selective detection of nitrobenzene through deferasirox based new fluorescent sensor

A deferasirox based substituted triazole amine sensor TAD has been synthesized for the highly selective detection of nitrobenzene in real samples. Sensor TAD exhibited selective quenching response against nitrobenzene among the other nitroaromatic compounds (NACs). Photoinduced electron transfer (PET) process was devised as plausible sensing mechanisms which was supported via UV–visible and fluorescence spectroscopy, 1H NMR titration experiment, density functional theory (DFT) analysis and Job’s plot. Non-covalent interaction (NCI) analysis and Bader’s quantum theory of atoms in molecules (QTAIM) analysis were performed to investigate the presence of non-covalent interactions and symmetry perturbation theory (SAPT0) was performed for energy decomposition and quantitative analysis of interaction energies between sensor TAD and NB. Furthermore, sensor TAD was practically applied for the identification of NB in real samples.

Enhanced electrochemical detection of nitrobenzene using zinc oxide-carboxylated graphene oxide composite as sensor

This study focused on the electrochemical detection of nitrobenzene (NB) using a glassy carbon electrode (GCE) modified with carboxylated graphene oxide (c-GO) that contained zinc nanoparticles (ZnO@c-GO/GCE). ZnO@c-GO nanocomposite modified GCE structural studies using SEM, XRD, and XPS showed that ZnO nanoparticles were successfully incorporated into c-GO nanosheets. Through the cooperative action of c-GO nanosheets and ZnO nanoparticles, electrochemical studies using electrochemical impedance spectroscopy, cyclic voltammetry, and amperometry demonstrated that the presence of ZnO nanoparticles and c-GO facilitated electron transfer between the redox probe and the electrode surface. Results showed that ZnO@c-GO/GCE had a broad linear sensitivity range of 0.1091 μA/μM, a considerably low limit of detection of 0.013 μM, and a linear range of 100–3000 μM. The prepared real sample of industrial wastewater samples used in the study to determine the precision of the proposed sensor for NB determination revealed significant recovery values (over 94.50 %) and acceptable accuracy (RSD less than 4.21 %), indicating that ZnO@c-GO (2:3)/GCE can be used as a precise NB electrochemical sensor in environmental applications.

Cover Feature: Five Novel Silver‐Based Coordination Polymers as Photoluminescent Sensing Platforms for the Detection of Nitrobenzene (Chem. Eur. J. 49/2023)

Cover Feature: Five Novel Silver‐Based Coordination Polymers as Photoluminescent Sensing Platforms for the Detection of Nitrobenzene (Chem. Eur. J. 49/2023)

MOF-Conductive polymer composite electrode as electrochemical sensor of nitrobenzene

A metal-organic framework (MOF)-conductive polymer composite film modified electrode was constructed by drop casting using PCN-222(Fe) and p3HT-p3TPA copolymer. The composite materials were characterized by diffraction, spectroscopic and electron microscopic techniques, showing the uniform distribution of MOF particles in the polymer matrix with the original MOF structure maintained. Introduction of carboxylate groups to the polymer matrix enhances interaction between polymer and MOF particles, leading to enhanced electron transfer and better water stability. The modified electrode was used for electrochemical detection of nitrobenzene in aqueous solution with the wide linear detection ranges of 0.05μM-1.00μM (0.6572 μAμM-1) and 1.00μM-100μM (0.03304 μAμM-1) as well as a low detection limit of 0.047μM.

Five Novel Silver-Based Coordination Polymers as Photoluminescent Sensing Platforms for the Detection of Nitrobenzene.

Nitrobenzene (NB) is a highly toxic chemical and a cause for concern to human health and the environment. Hence, it is worthwhile to design new efficient and robust sensing platform for NB. In this study, we present three newly synthesized luminescent silver cluster-based coordination polymers, {[Ag10(StBu)6(CF3COO)4(hpbt)] (DMAc)2(CH3CN)2}n (hpbt = N,N,N',N'N",N"-hexa(pyridine-4-yl)benzene-1,3,5-triamine), [Ag12(StBu)6(CF3COO)6(bpva)3]n (bpva = 9,10-Bis(2-(pyridin-4-yl)vinyl)anthracene), and {[Ag12(StBu)6(CF3COO)6(bpb)(DMAc)2(H2O)2] (DMAc)2}n (bpb = 1,4-Bis(4-pyridyl)benzene) composed of Ag10, Ag12 and Ag12 cluster cores, respectively, connected by multidentate pyridine linkers. Besides, two new luminescent polymorphic silver(I)-based coordination polymers, [Ag(CF3COO)(dpa)]n (dpa = 9,10-di(4-pyridyl)anthracene) referred to as Agdpa (H) and Agdpa (R), where H and R denote the hexagon-like and rod-like crystal shapes, respectively, have been prepared. The coordination polymers exhibit highly sensitive luminescence quenching effect to NB, attributed to the π-π stacking interactions between the polymers and NB as well as the electron-withdrawing character of NB.

Flower-like copper sulfide-decorated boron-nitrogen co-doped carbon-modified glassy carbon electrode for selective and sensitive electrochemical detection of nitrobenzene in natural water

Developing efficient and sensitive electrochemical sensors is crucial to environmental pollutant detection. In this study, we prepared a copper sulfide-loaded boron-nitrogen co-doped carbon (CuS-BCN) composite using a hydrothermal method. The physicochemical properties were characterized by various techniques, which confirmed the successful preparation of CuS-BCN composites. After optimization, a CuS-BCN modified glassy carbon electrode (CuS-BCN/GCE) was developed as a senor and used for electrochemical detection of nitrobenzene (NB) via square wave voltammetry. Two detection ranges were obtained:0.5–150 μM and 150–1000 μM, with low detection limits of 0.12 μM. In addition, the sensor exhibited excellent repeatability, reproducibility, stability, and immunity against interference. CuS-BCN/GCE exhibited high sensitivity for detecting NB in actual water samples. Hence, in this study, a new and promising electrochemical sensor for the detection of NB was successfully fabricated.