Picric Acid In Aqueous Media Research Articles

The Preparation of Tetraarylethylene-Based Porous Polymer Nanoparticles for the Sensitive Detection of Picric Acid in Aqueous Media

The Preparation of Tetraarylethylene-Based Porous Polymer Nanoparticles for the Sensitive Detection of Picric Acid in Aqueous Media

Curcumin-derivatives as fluorescence-electrochemical dual probe for ultrasensitive detections of picric acid in aqueous media

We are reporting the two curcumin derivatives, ferrocenyl curcumin (Fc-cur) and 4-nitro-benzylidene curcumin (NBC), as a probe through dual modalities, i.e., fluorescence and electrochemical methods, for the detection of nitro-analytes, such as picric acid (PA). The probes exhibited aggregation-induced enhanced emission (AIEE), and the addition of picric acid (PA) demonstrated good and specific fluorimetric identification of PA in the aggregated state. By using density functional theory (DFT), the mechanism of picric acid's (PA) interactions with the probes was further investigated. DFT studies shows evidence of charge transfer from curcumin derivatives probe to picric acid resulting into the formation of an adduct. The reduction of trinitrophenol (PA) to 2, 4, 6-trinitrosophenol was investigated utilizing a probe-modified glassy carbon electrode (GCE) with a good detection limit of 9.63 ± 0.001 pM and 41.01 ± 0.002 pM, respectively, for Fc-cur@GCE and NBC@GCE, taking into account the redox behavior of the probe. The applicability of the designed sensor has been utilized for real-time application in the estimation of picric acid in several water samples collected from the different source.

Sensing of picric acid using an AIEE active “Turn Off” fluorescent probe derived from hydroxy naphthaldehyde and benzyloxy benzaldehyde

A novel Schiff base with AIEE characteristics has been developed and used as a chemosensor for picric acid in aqueous media. The Schiff base 1-((E)-((E)-(4-(benzyloxy) benzylidene) hydrazono) methyl) naphthalen-2-ol [BBHN] with strong fluorescence emission was obtained by the simple condensation of 1-(hydrazonomethyl)naphthan-2-ol and 4-benzoxy benzaldehyde. The characterization of BBHN was done using Fourier Transfer Infra-Red, UV–visible, Magnetic Resonance (1H and 13C) spectroscopy, and HRMS. The sensing behaviour of BBHN aggregates towards nitro explosive was then investigated. The aggregates of BBHN showed a quick, highly selective, and sensitive fluorescence ‘Turn Off’ response towards picric acid (PA) in an aqueous medium among various other nitroaromatics. The limit of detection was 4.04 µM with 2.03 × 106 M−1 as the quenching constant. The fluorescence “Turn Off” response in the presence of PA is mainly due to π-π interactions, and non-covalent hydrogen bonding interactions. Moreover, steady-state fluorescence lifetime measurement and Stern − Volmer plots reveal that the fluorescence quenching followed mixed quenching strategies.

Fluorophenyl-modified AIPE-active cationic Pt(II) complexes for detecting picric acid in aqueous media

Two new fluorophenyl-modified cationic cyclometalated Pt(II) complexes have been synthesized. The effects of the fluorophenyl substituents on the properties of the Pt(II) complexes were investigated systematically in comparison with a phenyl-modified complex. The absolute quantum yields of the complexes are significantly increased due to the presence of fluorophenyl groups. All complexes exhibit evident aggregation-induced phosphorescent emission activities in a CH3CN/H2O system. Furthermore, they can effectively detect picric acid (PA) in CH3CN/H2O. Among them, the complex with a 2,4-difluorophenyl group exhibits the lowest limit of detection at 0.09 μM. These complexes exhibit excellent selectivity for detecting PA in complicated environments and work well in real water samples. The luminescence quenching of the complexes is caused by photo-induced electron transfer.

Phenomenal performance of polysaccharide based microgel-nanocomposite template for distinctive binding of picric acid in aqueous medium and cancer cell recognition

The ever-increasing use of toxic compound has caused devastating environmental and health effect. Organic pollutants like aromatic nitro compounds are the most common contaminants which are carcinogenic as well. Among the nitro aromatic compound Picric Acid is the most toxic compound which is extensively used in explosives also. A fluorescent nanocomposite ChS@ZnO has been developed using modified chitosan encapsulated ZnO nanoparticles. It has improved mechanical strength, chelation ability, cell penetration potentiality and photo catalytic activity due to the presence of ZnO NPs. ChS@ZnO has been used selectively and specifically to detect picric acid (PA) (LOD = 1.4 ppm) in aqueous medium through photoinduced electron transfer (PET) process. The detection ability of PA is due to the synergistic relationship between ChS and ZnO photocatalyst. Besides ChS@ZnO has excellent antioxidant potency and chelation ability which has been established through radical scavenging from DPPH and FRAP assays. The composite has also been used for normal and cancer cell imaging purpose. The nontoxic material shows excellent cell viability and cell imaging capacity for HT-29 and HEK293 cells.

An AIPE-active fluorinated cationic Pt(II) complex for efficient detection of picric acid in aqueous media

A novel cationic Pt(II) complex 2 with 2-(2,4-difluorophenyl)pyridine as the cyclometalating ligand and 1,10-phenanthroline as the auxiliary ligand has been synthesized and fully characterized. This complex exhibits much higher aggregation-induced phosphorescent emission activity than that of a non-fluorinated complex 1 in CH3CN/H2O. The complex 2 demonstrates efficient detection on picric acid (PA) in CH3CN/H2O, providing a high quenching constant (KSV = 2.3 × 104 L/mol) and a low limit of detection (LOD = 0.26 µmol/L). In addition, complex 2 shows high selectivity for detection of PA in real water samples. Density functional theory calculations and proton nuclear magnetic resonance spectra suggest that the detection mechanism is attributed to the photo-induced electron transfer.

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

Ultralong organic room-temperature phosphorescence, multiple stimulus responsiveness and high-level anti-counterfeiting based on multifunctional carbazolyl imidazolopyridine

Ultralong organic room-temperature phosphorescence materials induced by host−guest doping and the underlying mechanism have become the current research focus. Furthermore, high-level anti-counterfeiting and information encryption require multifunctional luminescent materials. Here, CzIP and L-CzIP with push−pull electronic system are successfully constructed by imidazopyridine units and commercial/self-made carbazole. The comparison experiment results indicate that trace isomer doping not only shows slight influence on crystal stacking and molecular space conformation but also significantly changes fluorescence and phosphorescence spectra and phosphorescence lifetime by boosting intersystem spin–orbit coupling. Non-radiative relaxation of CzIP and L-CzIP can be effectively inhibited by polymethyl methacrylate (PMMA) doping but not for crystallize. PMMA doping further confirms intrinsic phosphorescent characteristic of L-CzIP, whose room-temperature phosphorescence lifetime (84.83 ms) is close to that of CzIP (100.14 ms). Concentration-dependent fluorescent and phosphorescent emission and dynamic phosphorescent emission are also observed for CzIP in PMMA film. More importantly, a new aminopyridine/CzIP-doped system gives room-temperature phosphorescence lifetimes of 657.56 ms and afterglow lifetimes of 4 s. Notably, CzIP also shows high-contrast mechanochromism, selective response and differentiation to HCl, CF3COOH, and CH3COOH, and excellent detection capability to picric acid in aqueous medium and solid state. Finally, various anti-counterfeiting and encryption patterns are successfully constructed based on multifunction of CzIP. This work not only provides a multifunctional luminous material but also more importantly provides a theoretical basis and experimental guidance for designing novel ultralong organic room-temperature phosphorescence materials and achieving high-level anti-counterfeiting and encryption.

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.

Fluorimetric quantification of picric acid in aqueous medium via smartphone and invisible ink applications using pyrene based sensor

• Simple imidazole-pyrene based sensor for quantification of picric acid in aqueous medium. • The fluorescent probe became non-fluorescent in presence of picric acid. • Addition of picric acid caused bare-eye color change from colorless to yellow. • Colorimetric detection of picric acid using smartphone ‘Color detector App’. • Detection of picric acid by the means of invisible ink applications. A simple imidazole-pyrene based sensor (1) has been developed by simple one step reaction and characterized by using common spectroscopic techniques. When various nitroaromatic compounds were incorporated to CH 3 CN:H 2 O (1:2, v/v) solution of 1 , the fluorescent probe turned non-fluorescent in presence of picric acid, upon irradiation at 310 nm. This was accompanied by negligible changes with other molecules along with fluorescent color change from bluish-green to colorless in case of picric acid. Also, the fluorimetric sensing of picric acid was done using smartphone and invisible ink applications. The sensor has been found efficient for the recognition of picric acid in aqueous medium.

AIE active triphenylamine-CF3 based α-cyanostilbenes for selective detection of picric acid in aqueous media and solid support

Two new CF3-substituted α-cyanostilbenes were synthesized and characterized by NMR, UV–visible, and fluorescence spectroscopies. Fluorescence emission of the compounds reveals polarity-dependent solvatochromic effects. Furthermore, both compounds show aggregation-induced emission in dioxane/water binary solutions. Results were supported by density functional theory calculations. Interestingly, the compounds display selective detection of picric acid with limits of detection on the order of 10−7 M. The results indicate that the position of a CF3 group on α-cyanostilbenes can be used to tune the aggregation-induced emission for monitoring traces of picric acid in aqueous media and solid support.

A metal complex based fluorescent chemodosimeter for selective detection of 2,4-dinitrophenol and picric acid in aqueous media.

This work describes the syntheses, characterization, crystal structures, absorption and emission spectra and DFT calculations of three dizinc(II) compounds of the composition [ZnII2L(μ1,1-N3)(N3)2] (1) [Zn2L'(2,4-dinitrophenolate)2] (2) and [Zn2L'(picrate)2] (3), respectively, (where HL is the 1 : 2 condensation product of 4-ethyl-2,6-diformylphenol and N-methylethylenediamine and H2L' (a diamino-diimino-diphenol system) is a new type of macrocyclic ligand). Compound 1 is water soluble and its aqueous solution exhibits intense fluorescence properties. 2,4-Dinitrophenol (DNP) and picric acid (PA) selectively quench the fluorescence intensity of 1 to a significant extent, revealing that 1 is a fluorescence sensor of DNP and PA. Compounds 2 and 3 were prepared by mixing 1 with DNP and PA. As a huge change in the system (acyclic to macrocyclic) occurs while exhibiting sensing behaviour, it is evident that 1 senses DNP and PA through a chemodosimetric approach in aqueous media. For sensing nitroaromatic compounds, compound 1 acts as (i) a rare chemodosimeter, (ii) a rare metal containing chemodosimeter and (iii) a rare fluorescent chemosensor in aqueous media. Based on the ESI-MS and single crystal X-ray structures, it has been possible to establish a mechanism for the conversion of the acyclic system in 1 to a new type of macrocyclic system in 2 and 3. It has been established from DFT calculations that ground state complexation via charge transfer and IFE can be considered as the major reason for the DNP/PA stimulated strong fluorescence quenching.

An aggregation-induced emission-active bis-heteroleptic ruthenium(ii) complex of thiophenyl substituted phenanthroline for the selective “turn-off” detection of picric acid

A bis-heteroleptic Ru(ii) polypyridine complex-based AIEgen has been developed for the selective detection of nitroaromatic explosive picric acid in aqueous media.

Self-assembled nanomaterials of naphthalene monoimide in aqueous medium for multimodal detection of picric acid

Picric acid (PA) is a menacing environmental pollutant on account of its high solubility in water. Extensive usage of picric acid as a handy chemical and go-to explosive in pharmaceutical and chemical industries has been posing alarming threats to the environment and public health. The detection of PA in aqueous medium and vapor state is extremely important for military and civilian safety. Here, we report the synthesis of water soluble 1, 8-naphthalimide (ANDI) and multimodal sensing applications of aggregated nano materials for nitro explosives such as picric acid (PA) in aqueous, solid surface and vapor phase. The ANDI nano aggregates demonstrated substantial selectivity and ultrasensitive detection of PA with exceptional quenching constant 7.23×106 M−1 and limit of detection 149 ppb. The quenching takes place due to ground state charge transfer complex formation between PA and ANDI. Equilibrium simulation and the potential of mean force calculations reveal that the ANDI self-assembly is stabilized by extensive π-π interactions and the primary driving force behind the recognition of PA by the assembly is van der Waals interactions. ANDI aggregates would be potential materials for the construction of low cost and light weight nitroaromatic explosive sensors for future application.

Tripodal pyridyl-imine capped gold nano-aggregates for selective detection of picric acid in aqueous media

In the present investigation, we have design and develop pyridyl-imine capped gold nanoaggregates; fully characterized via various spectroscopic techniques. The photophysical and electrochemical studies revealed that the developed pyridyl-imine capped gold nanoaggregates are proven to be selective sensor for picric acid with remarkable low detection limit within nano-molar concentration (15.0 nM) based on 3σ/K; a common constituent of many powerful explosives. The quenching of fluorescence intensity at λ 357 nm occurs which may ascribe to the electron transfer phenomenon exhibited by the electron rich receptor and emergence of red shift in fluorescence spectroscopy (λem 464 nm) after gradual addition of picric acid; a selective phenomenon towards the most electron deficient nitroaromatic (picric acid) sensing. Additionally, the results obtained for the analysis of spiked samples in real water samples such as river and tap water, show that the developed PA sensor is potentially applicable in the determination of trace PA explosive without any interference.

Synthesis of Melamine‐Formaldehyde Microcapsules Containing Polyfluorene for Fluorescent Detection of Picric Acid in Aqueous Medium

To detect nitroaromatic picric acid (PA) in water, polyfluorene (PF) encapsulated melamine‐formaldehyde microcapsules (PF@MFMs) were fabricated via in situ polymerizations. Because of the microcapsule structure, PF@MFMs were uniformly dispersed in water maintaining the blue fluorescence of PF in the capsules. The fluorescence intensity of PF@MFMs linearly decreased with increase in the PA concentrations with high limit of detection of 3.0 × 10−6 M. The addition of other nitroaromatic derivatives, which had structure similar to PA, or various ions did not affect the fluorescence of PF@MFMs, showing high specificity of the microcapsules toward PA.

A metal-enhanced fluorescence sensing platform for selective detection of picric acid in aqueous medium

Apart from national security and military purposes, it is also of great importance to detect picric acid (PA) in aqueous solution for pollution control. Herein, we report a gold nanoparticle (AuNP)-based sensor for detection of PA in aqueous condition, based on metal-enhanced fluorescence (MEF) of poly(allylamine)hydrochloride (PAH). Notable enhancement in fluorescence intensity is observed when PAH is incubated with Au@SiO2 nanoparticles, where silica shell controls the distance between gold core and PAH. Almost ∼280 fold enhancement is recorded when PAH is incubated with ∼45 nm diameter Au nanoparticles. A significant reduction in excited state lifetime followed the enhancement in fluorescence intensity, identifying the mechanism to be primarily obtained from the intrinsic radiative decay rate enhancement of PAH. The MEF sensor shows excellent selectivity for detection of PA in water, among similar electron deficient compounds via fluorescence quenching. The detection limit of the sensor is calculated to be 79 nM, in the linear range. Detection of PA is demonstrated in simulated water samples, where matrix effects are taken into account to assess the efficacy of the sensor.

Zn(II)-Based Coordination Polymer for Detection of Picric Acid in Aqueous Media and Treatment Effect against Deep Vein Thrombosis by Reducing P-ERK2 and p53 Expression.

The coordination polymers based on Zn(II) ions and the metal nodes which has chemical formula of {[Zn3(L)2(tib)2(H2O)2]·(DMF)2}n (1) was synthesized via using 1,3,5-tris(1-imidazolyl)benzene (tib) and 2,6-di(4-carboxylphenyl)pyridine-4-carboxylic acid (H3L) as ligands under solvothermal conditions. Given its strong luminescent emission at room temperature and the uncoordinated N-donor sites in the framework, the selective detection performance of 1 toward the nitroanalytes was studied, 1's sensitive fluorescence quenching reactions along with selectivity to the electron-deficient TNP over other analytes of nitro within the aqueous phase was studied via the method of fluorescence quenching titration. Furthermore, the treatment effect of the compound on the deep vein thrombosis (DVT) was evaluated. Firstly, the ELISA was carried out to determine IL-17A content. Then, the platelet function was determined via the western blot by measuring expression level of platelet activation signaling pathway protein p-ERK2 and p53.

Investigations on sensing of picric acid in aqueous medium via fluorescence quenching of quinine sulfate

This research describes systematic investigations on sensing of high explosives such as picric acid (PA), RDX, NTO, and trinitrotoluene (TNT) in aqueous medium via fluorescence quenching of quinine sulfate (QS). Although all the explosives exhibit fluorescence quenching of QS, highest response is observed for PA. Fluorescence quenching of [Formula: see text][Formula: see text]50% (in contrast to pristine QS) at [Formula: see text][Formula: see text]390 nm is observed for 10 nm (2.29 [Formula: see text]g of PA dissolved in 20 [Formula: see text]l of distilled water). The analysis of the Stern–Volmer (SV) plot implies dominance of static quenching mechanism in comparison to dynamic quenching mechanism. Furthermore, the effect of operational temperature on fluoresce quenching response for PA has been investigated, and values of enthalpy, entropy, and Gibbs free energy of interaction at various temperatures are estimated. The temperature-dependent studies reveal that fluorescence quenching is due to formation of strong hydrogen bonds, complemented by computational analysis.

Star-shaped thienoviologens for electrochromism and detection of picric acid in aqueous medium

Two star-shaped thienoviologens with good redox and emission properties are reported. The results indicate that the increasing number of thiophene rings can strongly weaken the electron-accepting ability and make its first reduction wave shifted to more negative position, accompanying the decrease of the fluorescence quantum yield. The star-shaped thienoviologens were used as electroactive materials to fabricate electrochromic devices, which showed three-colour changes modulated by the different voltages. The star-shaped thienoviologens were used to detect the picric acid (PA) in aqueous medium with good sensitivity and selectivity (Ksv,5a = 1.94 × 105 L/mol; Ksv,5b = 5.38 × 104 L/mol) due to their special molecular architecture and cathodic conjugated scaffold.