Search Results (23)

The development of less toxic nanoparticles capable of producing and selectively sensing organic pollutants remains a significant challenge in biological and environmental applications. In this study, ZnInS/ZnS quantum dots (QDs) were synthesized via an aqueous-phase doping approach to integrate manganese (Mn) and enhance the singlet oxygen quantum yield (SOQY). The as-synthesized QDs displayed an average particle size of 7.40 nm, prolonged photoluminescence lifetimes, and tunable emission characteristics. Introduction of Mn into the host QDs enhanced the absolute quantum yield by up to twofold at the optimal concentrations, while the increased concentrations resulted in reduced luminescence due to increased non-radiative recombination. The surface chemistry of stabilizing agents further improved the formation of singlet oxygen. Thioglycolic acid (TGA)- and gelatin-capped QDs generated higher SOQY than QDs capped with citrate and TGA. Furthermore, as-synthesized Mn-doped QDs detected different organic pollutants such as trinitrophenol (TNP), dichlorophenol (DCP), naphthalene (NP), phenanthrene (PH), and pyrene (PY). Among these pollutants, TNP showed quenching behavior, while the others showed enhancement behavior. The QDs detected 620 µM of TNP following a linear Stern–Volmer relationship. These results show the potential of water-soluble Mn–ZnInS/ZnS QDs as multifunctional nanoprobes for phototherapy and environmental sensing applications. Full article

To resolve thermodynamic uncertainties in global gas–particle partitioning and persistent organic pollutant transport, this work integrates polycyclic aromatic hydrocarbons (PAHs) into the CHASER V4.0 chemistry–climate model, presenting the first global online simulations of naphthalene (NAP), phenanthrene (PHE), pyrene (PYR), and benzo[a]pyrene (BaP) within this framework to study their fate in the atmosphere. Soot adsorption (K_SA(T)) is coupled with organic matter absorption (K_OA(T)) under an extended Dachs–Eisenreich dual-mode scheme. The coupled model was evaluated at urban, background, and Arctic stations, satisfactorily capturing the broad global spatial gradients (pooled spatial R = 0.78 on a log₁₀ scale; spatial FAC2 = 80% for BaP excluding severe sub-grid hotspots) and seasonal cycles (R = 0.62–0.93). The K_SA(T) scheme rectifies the under-prediction of the particle-bound fraction (φ) in cold high-latitude regions (increasing polar φBaP by up to ~0.6), inherent in the baseline K_OA(T) scheme. Sensitivity tests show that elevated elemental carbon (f_EC) enhances soot adsorption and particle-phase shielding against oxidation, extending the mean lifetime of BaP to 1.72 days (compared to 0.57–0.72 days for lighter congeners) and sustaining transoceanic outflow. Overall, this framework provides an essential tool for assessing transboundary toxicant transport, climate-sensitive health risks, and pollution mitigation policies. Full article

The remote detection of nitro compounds typically requires complex analytical procedures and expensive instrumentation, often resulting in prolonged analysis times. Fluorescence-based methods, which exploit the quenching of organic fluorophores in the presence of nitro analytes, offer a more practical and efficient alternative. Particularly promising is the use of excimer emission generated by bis-pyrene species (bis-Pyr), formed either through supramolecular interactions or covalent linkages. Regarding the latter, the integration of covalently linked bis-Pyr sensors onto polymer backbones, such as commercially available polyvinyl chloride (PVC), represents a highly attractive strategy. In this manuscript, we wish to report our recent findings on the mechanosynthesis of bis-pyrene-based PVC-supported chemosensors, and on studies of its fluorescence response towards common nitro-compound/explosive components, such as 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), taggant 2,3-dimethyl-2,3-dinitrobutane (DMDNB), pentaerythritol tetranitrate (PETN) and 2,4,6-trinitrophenol (picric acid, PA). For DNT, a selective fluorescence “turn-off” response was observed with a Stern–Volmer quenching constant as high as 1.15 × 10⁴ M⁻¹. Full article

Polyoxometalates (POMs) are anionic metal oxide nanoclusters with rich redox chemistry, making them promising candidates for photocatalysis. However, their strong UV-light absorption and rapid charge recombination hinder visible-light applications. This review focuses on covalent organic–inorganic hybridization as a modular strategy to engineer POMs for visible-light photoactivation. By grafting chromophoric ligands, metalloporphyrins, or organometallic complexes onto POM surfaces via robust covalent bonds (e.g., Si–C, P–C, C–C), two key photochemical pathways are enabled: (i) direct visible-light excitation of organic sensitizers followed by intramolecular charge transfer to/from POMs and (ii) modified ligand-to-metal charge transfer (LMCT) transitions in POMs via ligand-induced electronic structure perturbation. We discuss how organic ligands regulate POM frontier orbital energy levels (HOMO/LUMO), redox potentials, and photoresponse range, supported by experimental and density-functional theory (DFT) studies. We also review hybrid systems with organic photosensitizers (e.g., pyrene, boron dipyrromethene (BODIPY)), metalloporphyrins, and organometallic complexes (e.g., Ru(II), Ir(III)), emphasizing structure–activity relationships in electron-transfer efficiency, charge-separation lifetime, and catalytic performance (e.g., hydrogen evolution, selective oxidation). Finally, we outline current challenges and prospects for designing multifunctional POM hybrids with tailored visible-light photocatalytic properties. Full article

Microplastics (MPs) are recognised as emerging vectors for hydrophobic organic contaminants in aquatic environments due to their relatively large surface area and the diversity of their polymer chemistries compositions. This study investigates the sorption behaviour of two priority polycyclic aromatic hydrocarbons (PAHs), pyrene (PYR) and fluoranthene (FLU), onto six common MPs: poly(m-xylene adipamide) (PA-MXD6), high- and low-density polyethylene (HDPE, LDPE), polypropylene (PP), polyethylene terephthalate (PET), and polylactic acid (PLA). Sorption isotherms and kinetics were evaluated under simulated freshwater conditions at environmentally relevant concentrations (1–50 µg·L⁻¹). Despite the low MP concentration used (0.2 g·L⁻¹), over 80% of the initial PAH content was removed by polyolefins, and more than 50% by all other MPs. Sorption capacity was strongly dependent on particle surface area. Langmuir, Henry, and Freundlich isotherms models were fitted, with linear behaviour prevailing at low concentrations. Analysis using the Dubini–-Radushkevich model confirmed that sorption involves chemisorption contributions, mainly through π–π interactions and hydrophobic interactions (polyolefins). Mechanistically, molecular diffusion within the MP matrix was not governing the sorption process, as diffusion coefficients varied with particle size instead of polymer chemistry. Instead, sorption appears to be governed by PAH diffusion through the hydrodynamic boundary layer and subsequent retention on the MP surface. Empirically, kinetic data fitted the pseudo-second-order model, further supporting that the sorption process involves chemisorption. These findings highlight the role of MPs as vectors for PAHs in freshwater systems and their potential application in contaminant removal. Expressing sorption per unit surface area is recommended for accurate assessment. This work contributes to understanding the environmental behaviour of MPs and their implications for pollutant transport and toxicity. Full article

In ecotoxicological risk assessment, current methods for measuring the transfer and bioavailability of organic pollutants like polycyclic aromatic hydrocarbons (PAHs) in bioindicators are often destructive and environmentally unfriendly. These limitations are especially problematic when only small amounts of biological material are available. Here, we present a novel, high-throughput method combining laser-induced UV fluorescence spectroscopy (UV-LIF) and solid-phase spectroscopy (SPS) for rapid, in situ quantification of PAHs in land snails—a key bioindicator species. Using dual excitation wavelengths (266 nm and 355 nm), our method reliably detected pyrene and fluoranthene in snails exposed to varying concentrations, demonstrating clear dose-responses and inter-individual differences in bioaccumulation. The analysis time per sample was under four minutes. This approach allows simultaneous measurement of internal contaminant levels and health biomarkers in individual organisms and aligns with green chemistry principles. These findings establish a new, scalable tool for routine assessment of PAH transfer and bioavailability in diverse ecosystems. Full article

Benzo[a]pyrene (B[a]P) is a hazardous polycyclic aromatic hydrocarbon that accumulates in several environmental matrices as a result of incomplete combustion. Its presence, carcinogenic properties, and tendency for bioaccumulation provide significant risks to human health and the environment. The objective of this study is to create an immunoassay for the detection of benzo[a]pyrene utilizing immunoglobulin Y antibodies. An indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was utilized to develop a speedy, straightforward, sensitive, and economical approach for detecting B[a]P residues. Following the immunization of hens with the hapten pyrenebutyric acid-bovine serum albumin (PyBA-BSA), the IgY antibody extracted from egg yolk was utilized to identify B[a]P residues. To evaluate antibody specificity, six PAH derivatives—PyBA, B[a]P, Chrysene, Benzo[b]fluoranthene, Benzo[a]anthracene, and Benzo[k]fluoranthene—were examined in the experiment to compete for binding with PyBA. The findings indicate that the antibody had considerable affinity for Chrysene (1.15%), Benzo[b]fluoranthene (311.32%), Benzo[k]fluoranthene (10.62%), Benzo[a]anthracene (22.82%), and PyBA (9.55%). Nonetheless, its affinity for B[a]P remained at 100%. The recovery range for grilled pork samples spiked with B[a]P doses of 10.00–0.1 μg/mL was 74.99% to 143.11%. This study utilized a polyclonal antibody, employing the IgY antibody for the inaugural development of an immunoassay to detect benzo[a]pyrene. The ELISA had a higher IC₅₀ value compared to the other immunoassays; however, it yielded good results. This immunoassay signifies a substantial progression in environmental analytical chemistry, offering a cost-effective and accessible technique for the detection of B[a]P to protect human health and the environment. Full article

Pyrene, a renowned aromatic hydrocarbon, continues to captivate researchers due to its versatile properties and potential applications across various scientific domains. Among its derivatives, bromopyrenes stand out for their significance in synthetic chemistry, materials science, and environmental studies. The strategic functionalisation of pyrene at non-K region and nodal positions is crucial for expanding its utility, allowing for diverse functionalisation strategies. Bromo-substituted precursors serve as vital intermediates in synthetic routes; however, the substitution pattern of bromoderivatives significantly impacts their subsequent functionalisation and properties, posing challenges in synthesis and purification. Understanding the distinct electronic structure of pyrene is pivotal, dictating the preferential electrophilic aromatic substitution reactions at specific positions. Despite the wealth of literature, contradictions and complexities persist in synthesising suitably substituted bromopyrenes due to the unpredictable nature of substitution reactions. Building upon historical precedents, this study provides a comprehensive overview of bromine introduction in pyrene derivatives, offering optimised synthesis conditions based on laboratory research. Specifically, the synthesis of mono-, di-, tri-, and tetrabromopyrene isomers at non-K positions (1-, 3-, 6-, 8-) and nodal positions (2-, 7-) is systematically explored. By elucidating efficient synthetic methodologies and reaction conditions, this research contributes to advancing the synthesis and functionalisation strategies of pyrene derivatives, unlocking new possibilities for their utilisation in various fields. Full article

In recent years, transition metal-catalyzed C–H activation and site-selective functionalization have been considered to be valuable synthetic tactics to functionalize organic compounds containing multiple C–H bonds. Pyrene is one of the privileged and notorious polycyclic aromatic hydrocarbons. Pyrene and its derivatives have found applications in various branches of chemical sciences, including organic chemistry, chemical biology, supramolecular sciences, and material sciences. Given the importance of pyrene derivatives, several classical methods, including the C–H functionalization method, have been developed for synthesizing modified pyrene scaffolds. This review attempts to cover the recent developments in the area pertaining to the modification of the pyrene motif through the C–H activation process and the functionalization of C–H bonds present in the pyrene motif, leading to functionalized pyrenes. Full article

Novel nanostructured platforms based on Pencil Graphite Electrodes (PGEs), modified with pyrene carboxylic acid (PCA) functionalized Reduced Graphene Oxide (rGO), and then decorated by chronoamperometry electrodeposition of MoS₂ nanoroses (NRs) (MoS₂NRs/PCA-rGO/PGEs) were manufactured for the electrocatalytic detection of hydrazine (N₂H₄) and 4-nitrophenol, pollutants highly hazardous for environment and human health. The surface morphology and chemistry of the MoS₂NRs/PCA-rGO/PGEs were characterized by scanning electron microscopy (SEM), Raman, and X-ray photoelectron spectroscopy (XPS), assessing the coating of the PCA-rGO/PGEs by dense multilayers of NRs. N₂H₄ and 4-nitrophenol have been monitored by Differential Pulse Voltammetry (DPV), and the MoS₂NRs/PCA-rGO/PGEs electroanalytical properties have been compared to the PGEs, as neat and modified by PCA-rGO. The MoS₂NRs/PCA-rGO/PGEs demonstrated a higher electrochemical and electrocatalytic activity, due to their high surface area and conductivity, and very fast heterogeneous electron transfer kinetics at the interphase with the electrolyte. LODs lower than the U.S. EPA recommended concentration values in drinking water, namely 9.3 nM and 13.3 nM, were estimated for N₂H₄ and 4-nitrophenol, respectively and the MoS₂NRs/PCA-rGO/PGEs showed good repeatability, reproducibility, storage stability, and selectivity. The effectiveness of the nanoplatforms for monitoring N₂H₄ and 4-nitrophenol in tap, river, and wastewater was addressed. Full article

The globally widespread perfluorooctanoic acid (PFOA) is a concerning environmental contaminant, with a possible toxic long-term effects on the environment and human health The development of sensible, rapid, and low-cost detection systems is a current change in modern environmental chemistry. In this context, two triamine-based chemosensors, L1 and L2, containing a fluorescent pyrene unit, and their Zn(II) complexes are proposed as fluorescent probes for the detection of PFOA in aqueous media. Binding studies carried out by means of fluorescence and NMR titrations highlight that protonated forms of the receptors can interact with the carboxylate group of PFOA, thanks to salt bridge formation with the ammonium groups of the aliphatic chain. This interaction induces a decrease in the fluorescence emission of pyrene at neutral and slightly acidic pH values. Similarly, emission quenching has also been observed upon coordination of PFOA by the Zn(II) complexes of the receptors. These results evidence that simple polyamine-based molecular receptors can be employed for the optical recognition of harmful pollutant molecules, such as PFOA, in aqueous media. Full article

The solubilization capacity of a series of sustainable phenylalanine-derived surface-active ionic liquids (SAILs) was evaluated towards polycyclic aromatic hydrocarbons—naphthalene, anthracene and pyrene. The key physico-chemical parameters of the studied systems (critical micelle concentration, spectral properties, solubilization parameters) were determined, analyzed and compared with conventional cationic surfactant, CTABr. For all studied PAH solubilization capacity increases with extension of alkyl chain length of PyPheOC_n SAILs reaching the values comparable to CTABr for SAILs with n = 10–12. A remarkable advantage of the phenylalanine-derived SAILs PyPheOC_n and PyPheNHC_n is a possibility to cleave enzymatically ester and/or amide bonds under mild conditions, to separate polycyclic aromatic hydrocarbons in situ. A series of immobilized enzymes was tested to determine the most suitable candidates for tunable decomposition of SAILs. The decomposition pathway could be adjusted depending on the choice of the enzyme system, reaction conditions, and selection of SAILs type. The evaluated systems can provide selective cleavage of the ester and amide bond and help to choose the optimal decomposition method of SAILs for enzymatic recycling of SAILs transformation products or as a pretreatment towards biological mineralization. The concept of a possible practical application of studied systems for PAHs solubilization/separation was also discussed focusing on sustainability and a green chemistry approach. Full article

Entropy is a measure of a system’s molecular disorder or unpredictability since work is produced by organized molecular motion. Shannon’s entropy metric is applied to represent a random graph’s variability. Entropy is a thermodynamic function in physics that, based on the variety of possible configurations for molecules to take, describes the randomness and disorder of molecules in a given system or process. Numerous issues in the fields of mathematics, biology, chemical graph theory, organic and inorganic chemistry, and other disciplines are resolved using distance-based entropy. These applications cover quantifying molecules’ chemical and electrical structures, signal processing, structural investigations on crystals, and molecular ensembles. In this paper, we look at K-Banhatti entropies using K-Banhatti indices for $C_6{H}_6$ embedded in different chemical networks. Our goal is to investigate the valency-based molecular invariants and K-Banhatti entropies for three chemical networks: the circumnaphthalene ($CN{B}_n$), the honeycomb ($H{B}_n$), and the pyrene ($P{Y}_n$). In order to reach conclusions, we apply the method of atom-bond partitioning based on valences, which is an application of spectral graph theory. We obtain the precise values of the first K-Banhatti entropy, the second K-Banhatti entropy, the first hyper K-Banhatti entropy, and the second hyper K-Banhatti entropy for the three chemical networks in the main results and conclusion. Full article

Artificial gene delivery systems are in great demand from both scientific and practical biomedical points of view. In this paper, we present the synthesis of a new click chemistry calix[4]arene precursor with free lower rim and new water-soluble calixarene triazoles with 12 amino-groups on the upper rim (one with free phenol hydroxyl groups and two another containing four butyl or tetradecyl fragments). Aggregation in the series of amino-triazole calixarenes of different lipophilicity (calixarene with free phenol hydroxyl groups or butyl and tetradecyl fragments on the lower rim) was studied using dynamic light scattering and fluorescent pyrene probe. It was found that calix[4]arene with a free lower rim, like alkyl-substituted butyl calix[4]arene, forms stable submicron aggregates 150–200 nm in size, while the more lipophilic tetradecyl –substituted calix[4]arene forms micellar aggregates19 nm in size. Using UV-Vis spectroscopy, fluorimetry and CD, it was shown that amino-triazole calix[4]arenes bind to calf thymus DNA by classical intercalation. According to DLS and TEM data, all studied macrocycles cause significant DNA compaction, forming stable nanoparticles 50–20 nm in size. Among all studied calix[4]arenes the most lipophilic tetradecyl one proved to be the best for both binding and compaction of DNA. Full article

A simple synthetic method was designed, in which the Sonogashira coupling reaction and [2+2] cycloaddition click reaction with high yield were performed on 1-bromopyrene to obtain several novel pyrene derivatives. The structure of each sample was characterized by Nuclear Magnetic Resonance (NMR), Mass Spectrometry (MS), Fourier transform infrared (FTIR) and elemental analysis. The characterization of the products by Ultraviolet-visible (UV-vis) and Photoluminescence (PL) spectroscopy proves that the addition of click groups has an important effect on the optoelectronic properties of pyrene derivatives. The Z-scan technique was used to test the third-order nonlinear optical (NLO) properties of the samples, and it could be found that the NLO properties of the products were improved and the transition of saturable absorption and reverse saturable absorption occurred with the addition of click reagent. These factors indicate that the click-modified pyrene derivatives have potential applications in areas such as optical limiting. Full article