Selective Detection Of Picric Acid Research Articles

Selective Detection of Picric Acid by Benzodiazepine Containing Enaminone Core as Receptor and Its Application to Real Water Sample Analysis.

Nitroaromatic compounds are highly explosive and illegitimate substances. Over a decade, chemists have been affianced in extensive research on the selective and sensitive detection of these nitroaromatic explosives for homeland security and environmental protection. The benzodiazepine-based enaminone (BDE) receptor has been synthesized by aqueous extract of onion catalyzed three-component reaction between o-phenylenediamine, dimedone with an aldehyde. The BDE probe is well analyzed and applied to a sensor that selectively detects picric acid (PA). UV-Vis and fluorescence spectroscopy were used to investigate the photophysical responses of the receptor (BDE). From the observed results BDE found turn-off fluorescence with the addition of picric acid and the lowest limit of detection and limit of quantification was achieved about 24.6 nM and 73.8 nM. The fluorescence quantum yield was attained about 0.28. The BDE-PA adduct formation was confirmed by 1H NMR titration analysis. The Job's plot analysis was performed through 1H NMR titrations and established the binding stoichiometry ratio of the BDE-PA adduct as 1:1 ratio. Further, DFT calculations supported the observed photophysical responses of BDE-PA adduct to confirm the molecular level interactions. The receptor was effectively applied to approximate level of picric acid in real water sample analysis.

An Imidazole-Naphthalimide-Based pH-Sensitive Molecular Probe for Selective Detection of Picric Acid and Cell Imaging

An Imidazole-Naphthalimide-Based pH-Sensitive Molecular Probe for Selective Detection of Picric Acid and Cell Imaging

Pyrene based AIE-active probe for selective detection of picric acid through the inner filter effect channel in aqueous medium

The development of pyrene derivatives possessing the AIE feature have emerged as an intriguing area of research with potential applications in several domains. In the present study, we designed and developed an AIE active pyrene derivative for picric acid sensing in an aqueous medium. The design based on a single step condensation reaction and the product has been meticulously characterized by using NMR and Mass spectrometric techniques. In comparison to pristine pyrene, the synthesized pyrene derivative has a lower bandgap energy as a result of the intramolecular charge transfer between pyrene and 4-(methylthio)-2-oxo-2H-pyran-3-carbonitrile. The synthesized probe demonstrates a moderate level of fluorescence when dissolved in a solution, and it has exhibited a remarkable emission caused by aggregation at higher water percentages. The aggregates were meticulously characterized by DLS, SEM and TEM measurements. The spherically shaped aggregates have shown enhanced fluorescence quantum yield and lifetime, rendering them a more suitable option for sensor applications. The aggregates were effectively employed as a fluorescent probe for the detection of picric acid in an aqueous medium. The probe exhibited a notable level of selectivity and sensitivity towards picric acid, as evidenced by its low detection limit of 4.47 nM. Moreover, the quenching mechanism was ascribed to the inner filter effect, providing supporting evidence from both experimental and mathematical calculations. The findings indicate that the probe has potential as a feasible choice for a picric acid sensor.

Design, synthesis, and spectrofluorimetric analysis of a novel fluorene-based chemosensor for the selective detection of picric acid

Fluorene-based probes are efficient candidates for sensing nitroaromatics and toxins. A novel fluorophore based on fluorene and terephthalaldehyde 1,4-YBF (1,4-ylidene-bis-fluorene) has been designed and synthesized for the efficient sensing of 2,4,6-trinitrophenol (picric acid) in solution. X-ray crystallographic studies, NMR, and mass analyses revealed the molecular stacking and exact structure of 1,4-YBF, which was further structurally optimised using the DFT technique. The optical properties of the newly synthesized compound were studied using UV–Vis and spectrofluorimetric analyses. The fluorophore was subjected to detailed sensing studies of various nitroaromatics, among which it was identified that picric acid (PA) exhibited the maximum quenching efficiency. The excellent sensing ability of the fluorophore was probably attributed to the photoinduced electron transfer (PET) mechanism. Further, pH studies and interference studies, along with its high selectivity towards PA and an LOD of 0.314 µM, revealed 1,4-YBF to be efficient in the detection of picric acid at a micromolar level.

Retraction Note: Multifunctional Zinc Metal–Organic Framework for Highly Selective Detection of Picric Acid and Inhibition of Laryngeal Cancer Cell Growth

Retraction Note: Multifunctional Zinc Metal–Organic Framework for Highly Selective Detection of Picric Acid and Inhibition of Laryngeal Cancer Cell Growth

Synthesis and fluorescence properties of 2′-benzyloxy flavone—a dual probe for selective detection of picric acid and pH sensing

2′-Benzyloxy flavone as a novel dual fluorescent probe for picric acid and pH sensing.

Synthesis of pyridyl functionalized 3-pyrrolyl BODIPY based fluoroprobes and application towards highly selective detection of picric acid.

A series of pyridyl-coupled 3-pyrrolyl BODIPY fluoroprobes were synthesized by varying the position of the pyridyl/N-methylated pyridyl group at the α-/meso-position of the 3-pyrrolyl BODIPY scaffold and thoroughly characterized by HRMS and 1D/2D NMR techniques. Our studies indicated that only the water-soluble N-methylated p-pyridyl 3-pyrrolyl BODIPY among various pyridyl-coupled 3-pyrrolyl BODIPYs synthesized here showed an effective and exclusive sensing for picric acid (HPA). The N-methylated p-pyridyl 3-pyrrolyl BODIPY rapidly detects HPA in an aqueous medium with exceptional selectivity, sensitivity (LOD = 7.90 pM), and high binding affinity (Ka = 4·94 × 108 M-1) through both chromogenic and fluorogenic signalling modes. Our studies support the formation of a charge transfer complex between cationic N-methylated p-pyridyl 3-pyrrolyl BODIPY and picrate as verified by absorption, fluorescence, electrochemical, and NMR techniques. DFT and TD-DFT studies further support the structural and experimental observations, including the sensing mechanism of HPA.

A Type of Conjugated Fuse Heterocyclic Schiff Base Colorimetric andFluorescent Chemosensors for Selective Detection of Picric acid (PA)

: A series of Schiff base chemosensors (M1, M2 and M3) were designed and synthesized based on conjugated fuse heterocyclic aldehyde thiosemicarbazone. Optical properties of fluorescent probes M1, M2, and M3 toward various nitro explosives 2,4-dinitrotoluene (DNT), o-nitrophenol (ONP), p-nitrophenol (PNP), phenol (PhOH) and nitromethane (NM) were investigated, M1, M2, and M3 could selectively recognize PA with an obvious color change and fluorescence quenching, even in the presence of other coexistence nitro explosives. The detection limit of M1, M2, and M3 were 1.18and#215;10-7 M, 1.13and#215;10-7 M, 1.09and#215;10-7 M, respectively.

Tridentate chelating ligand based fluorescent Zn(ii) coordination compounds for highly selective detection of picric acid

Two Zn(ii) complexes with 1-((2-pyridylmethyl)iminomethyl)-2-naphthol ligand show sensitive response to nitroaromatic explosives through luminescence quenching effects. The phenomenon was studied through time-dependent fluorescence technique.

Dual functional porous organic polymer: Reversible iodine capture and selective sensing of picric acid

The development of porous organic materials for removing radiotoxic iodine from nuclear plant waste is significantly relevant to environmental remediation as well as the detection of trace amounts of nitroexplosive picric acid for environmental safety is challenging. To achieve reversible iodine adsorption by the porous material, we have synthesized a highly stable porous organic polymer POF-1 by Schiff base condensation of tris(4-aminophenyl)methane and 2,2′-bithiophene-5,5′-dicarbaxaldehyde under microwave irradiation. POF-1 showed high affinity towards iodine adsorption due to electron-rich sulfur and nitrogen atoms in the porous structure which interact with iodine and form polyiodide ions by electrostatic interactions. POF-1 showed a remarkable iodine uptake capacity of 4.25 g g−1 in the vapor phase and could efficiently remove iodine from an iodine-cyclohexane solution with an adsorption efficiency of 141.0 mg/L. The iodine adsorption follows Langmuir's isothermal model i.e. monolayer adsorption and Pseudo second-order kinetics. POF-1 exhibited good recyclability towards reversible iodine capture even after five cycles. Furthermore, the luminescence characteristic of POF-1 has been employed for the selective detection of picric acid with high sensitivity with a detection limit of 8 μM among a range of nitroaromatic. The Fluorescence quenching mechanism is mainly attributed to photo-induced electron transfer and the inner filter effect.

Phenoxazine-based supramolecular metal-organic cage for picric acid detection

A phenoxazine-based metal-organic cage Zn2L3 (L = N-n-butyl-3, 7-dipyridine phenoxazine) was synthesized by the coordination-driven self-assembly, which could work as a fluorescent sensor for sensitive and selective detection of picric acid (PA) among nitro-explosives. The cage contains three V-shaped ligands L linked by zinc ions, and the fluorescence of the ligands is preserved and transferred to the cage. Different from the free phenoxazine-based ligand, Zn2L3 showed strong emission at 568 nm and exhibited the highest fluorescence quenching efficiency toward picric acid over other related nitroaromatic explosives. The cage structure with cavities exhibits the better sensing property than monomeric ligand. Electrospray ionization mass spectrometry (ESI-MS), NMR and fluorescence titration suggested that the formation of host–guest complex of the cage with the picric acid target, should be thought as the key factor for its nice recognition ability.

Chemodosimetric Mechanistic Insight through Trapping Intermediate for Selective Detection of Picric Acid in Aqueous Medium by a Dinuclear CdII Complex

AbstractA fluorescent dinuclear cadmium(II) based discrete metal complex of composition [CdII2L(μ‐Cl)Cl2](1) is used {HL=2,6‐bis[2‐(methylamino)ethyliminomethyl]‐4‐Ethylphenol} for the specific recognition of 2,4,6‐trinitrophenol (picric acid; PA) via fluorescence quenching phenomenon among various nitroaromatic compounds through a chemodosimetric approach. It has been established that 1 is a chemodosimeter in pure water. We have successfully been able to isolate three compounds: chemodosimeter 1; an intermediate complex 2 of composition [CdII(LH2)Cl2](Picrate) and final association complex 3 of composition [NH3(CH2CH2)NH2CH3](Picrate)2. Compounds have been characterised by CHN elemental analyses, single crystal X‐ray crystallography, PXRD, NMR and FTIR. Selective interaction of 1 with PA was evaluated by fluorescence, UV‐Vis and life time measurements. Fluorescence quenching of 1 occurs definitely due to the formation of compound 3 via intermediate 2 involving partial decomplexation, hydrolysis and proton transfer phenomena in solution during the course of sensing. The quenching constant (Ksv), association constant (Ka) and detection limit (LOD) of the complex 1 for picric acid are ∼1.55×105 M−1, ∼1.8×1010 M−2 and ∼0.47 μM (0.108 ppm), respectively. Mechanism of sensing is proposed and the very rare case of isolation and characterization of intermediate in picric acid sensing is discussed.

Photoluminescent pyrene-based ionic liquid derived ratiometric organo nanosensor for rapid and selective detection of picric acid

Due to the rising menace of illicit actions and pollution aroused by explosive nitroaromatic compounds (NACs), the growth of an adept sensor for detecting these NACs is highly essential. Herein, in this communication, a photoluminescent IL-assimilated group of uniform materials based on organic salt (GUMBOS) and nano-GUMBOS has been fabricated by integrating pyrene butyrate with a quaternary phosphonium IL (PbIL) via a simple ion exchange process. Neat PbIL shows a bright cyan color photoluminescence under a 365 nm UV lamp irradiation and is employed as photoluminescence security ink and picric acid (PA) detection among the tested NACs. By simple reprecipitation method, we have developed water-suspended crystalline pyrene assimilated nanoparticles, nPbIL, characterized by various analytical techniques. The PbIL-derived water-suspended nanomaterials, nPbIL, display a robust cyan color excimer-like emission, which turns blue (monomeric) due to adding PA over the other related NACs. This ratiometric cyan to blue photoluminesce change is due to the displacement of the anionic pyrene moiety of the nPbIL by the picrate anion. The fabricated organo nanosensor is enormously discerning and responsive towards PA with a detection limit of 0.77 nM and is found to be superior to many available in the literature. Additionally, a fluorogenic paper strip-based test kit experiment has been demonstrated to detect and quantify PA selectively in aqueous solvents amongst the other tested NACs. The present contribution evokes a novel approach to developing different IL-based chemosensors for detecting and quantifying various target analytes.

Selective detection of picric acid in aqueous medium using a novel naphthaldehyde-based aggregation induced emission enhancement (AIEE) active “turn-off” fluorescent sensor

Selective detection of picric acid in aqueous medium using a novel naphthaldehyde-based aggregation induced emission enhancement (AIEE) active “turn-off” fluorescent sensor

Blue-Emissive Nitrogen-Doped Carbon Dots for Picric Acid Detection: Molecular Fluorescence Quenching Mechanism

We report a molecular fluorophore-based concept for the first time, to explain the quenching mechanism of the blue-emissive N-doped carbon dots (NCDs) exhibiting molecular fluorescence (quantum yield = 37%), synthesized through microwave-assisted pyrolysis of malic acid and urea (in 1:3 mole ratio), which has been devised as a fluorescent probe for the sensitive and selective detection of picric acid (PA). A linear Stern–Volmer plot for the fluorescence quenching of NCDs in the PA detection has been observed in the concentration range of 0–1.6 μM, and the limit of detection (LOD) is found to be 33 nM (7.56 ppb). Furthermore, molecular fluorescence in NCDs has been realized to originate from a putative pyridinic (2-pyridone moiety)-type molecular fluorophore, which has been manifested by the inferences drawn from HRMS, 1H NMR, 13C NMR, and XPS studies. The chemical structure of the molecular fluorophore was further validated by correlating the simulated absorption and emission spectra of the molecular fluorophore generated by TD-DFT, with those obtained from NCDs’ experimental data. The underlying photophysical property involved in the simultaneous occurrence of FRET and ET quenching mechanism has been illustrated based on the molecular fluorophore, along with the conventional approach. Here, the role of the molecular fluorophore in the NCDs has been demonstrated as a donor in the ET process involving the NCDs–nitroaromatics pair, where the acid–base interaction between the acceptor (nitroaromatics) and donor has been considered as the essence of the ET process.

Triazole-based pyrene-sugar analogues for selective detection of picric acid in water medium and paper strips

Triazole-linked pyrene-appended inexpensive sensors 1 and 2 were synthesized from carbohydrates to instantly recognize picric acid (PA) based on a charge-transfer mechanism in the semi-water medium. Both sensors showed good selectivity and sensitivity towards PA over a wide variation of nitroaromatics in the absorbance and fluorescence methods. Moreover, sensors 1 and 2 were used for quick finding of picric acids using test strips. Interestingly, it was found that the sensitivity of 2 (LOD: 0.012 µM) is higher than 1 (LOD: 0.093 µM) might be explained by the close intramolecular space of the triazole/sugar residue and pyrene in sensor 2. The fluorescence quenching and structural features of the complexes (1-PA, 2-PA) were supported by density functional theory (DFT) calculations and spectroscopic studies.

Two-dimensional ion–molecule chelation reaction (2D-IMCRs) to form a two-dimensional dual optical sensor (2D-DOS): synthesis and application of Phen-SnO2 nanosheets for the fluorometric and colorimetric sensing of nitroaromatic explosives

Organic precursor-modulated fluorescent 2D Sn-nanosheets are investigated for the selective detection of picric acid. The findings have potential for the environmental monitoring of nitroaromatic compounds.

3D printed optical sensor for highly sensitive detection of picric acid using perovskite nanocrystals and mechanism of photo-electron transfer

Hand-held, compact and portable sensors for on-site detection of environmental contaminants are in high demand for industry 4.0. Here, we have developed a sensor based on luminescent organic–inorganic metal halide hybrid perovskites nanocrystals (CH3NH3PbBr3) with p-xylylenediamine as an additional capping agent for highly sensitive and selective detection of picric acid (PA), with a good linear range of 1.8 μM–14.3 μM achieving detection of limit (LOD) of 0.3 μM. The electrostatic interaction between PA and the capping ligand of perovskite nanocrystals resulted in significant fluorescence quenching, as revealed by the steady-state and time-resolved spectroscopy. The applicability of the developed sensor for PA detection was validated with a 3D printed device integrating surface mounting device (SMD) and paper microfluidics. This prototype device was successfully applied as a fluorescence turn-off sensor to detect PA, showing great potential for on-site detection. This 3D-printed paper-based microfluidic optical sensor proved very efficient for naked-eye detection of PA with an inbuilt excitation source, avoiding the requirement of expensive and complex instrumentation.

Highly sensitive, selective and reliable detection of picric acid in aqueous media based on conjugated porous polymer nanoparticles

Conjugated porous polymer is known as a promising sensing material for detecting nitroaromatic compounds, however, the sensing application in aqueous media is restricted, due to their poor solubility/dispersity in water. Herein, two novel conjugated porous polymer nanoparticles (PTPA-TPE1 and PTPA-TPE2) containing triphenylamine in the backbone and tri/tetraphenylethene as side groups were designed and synthesized. PTPA-TPE1 and PTPA-TPE2 were fully characterized by FT-IR, 1H NMR, TEM, N2 sorption isotherms, UV–vis absorption spectra, photoluminescence (PL) spectra and cyclic voltammetry. The electron-rich triphenylamine backbones benefit the interaction with nitroaromatics and the porosity could promote the adsorption/diffusion of the analytes. The PL sensing properties of the polymers were evaluated in aqueous dispersion, and the detection limits of PTPA-TPE1 and PTPA-TPE2 towards picric acid (PA) are 72 ppb and 111 ppb, respectively. Importantly, the PL quenching effect towards PA exhibits no noticeable change upon the addition of other nitroaromatic compounds, indicating the anti-interference characteristic and selective detection of PA. Furthermore, at 95 % confidence level, there was no significant difference between the results of our sensing method and HPLC analysis for detecting PA in real environmental water samples by the t-test.

Rapid and selective detection of picric acid based on supramolecular self-assembly of a cationic perylene diimide in pure aqueous media

Detection of picric acid (PA) is of great significance to environmental protection and public safety. Most sensors reported for PA were constructed via a direct quenching approach. In this work, an innovative fluorescent probe based on perylene diimide derivative (PdE-PDI) has been designed from the self-assembly's point of view. The formation of supramolecular complex (PdE-PDI/PA) will lead to fluorescence quenching of the system, affording sensitive and selective detection of PA in 100% aqueous solution. Systematic investigation indicated the synergistic effect of non-covalent interactions resulted in the self-assembly PdE-PDI and PA, including static electricity, hydrophobic interaction, charge transfer and π-π stacking. The detection limit of the probe is 37 nmol L−1 and the linear range is of 0.2–1.4 μmol L−1, possessing good selectivity and anti-interference ability. The visual detection limit of the naked-eye fluorescence sensing of PA is 10 μmol L−1. Finally, this probe was successfully applied in the monitoring of PA in real samples, which achieve the recovery rate in the range of 80–113.3%.