Fluorescence Spectroscopy Research Articles

Investigating the Inhibition of Diindolylmethane Derivatives on SARS-CoV-2 Main Protease.

The SARS-CoV-2 main protease (Mpro) is an essential enzyme that promotes viral transcription and replication. Mpro conserved nature in different variants and its nonoverlapping nature with human proteases make it an attractive target for therapeutic intervention against SARS-CoV-2. In this work, the interaction mechanism between Mpro and diindolylmethane derivatives was investigated by molecular docking, enzymatic inhibition assay, UV-vis, fluorescence spectroscopy, and circular dichroism spectroscopy. Results of IC50 values show that 1p (9.87 μM) was the strongest inhibitor for Mpro in this work, which significantly inhibited the activity of Mpro. The binding constant (4.07 × 105 Lmol-1), the quenching constant (5.41 × 105 Lmol-1), and thermodynamic parameters indicated that the quenching mode of 1p was static quenching, and the main driving forces between 1p and Mpro are hydrogen bond and van der Waals force. The influence of molecular structure on the binding is investigated. Chlorine atoms and methoxy groups are favorable for the diindolylmethane derivative inhibitors of Mpro. This work confirms the changes in the microenvironment of Mpro by 1p, and provides clues for the design of potential inhibitors.

Enhancement of soil humic acid hydrophobicity by 5 consecutive years of full-amount straw shallow-mixed field return

Crop yield is directly influenced by the storage and stabilisation of soil organic carbon (SOC), which is determined by the hydrophobicity of soil humic acid (HA). Changes in soil HA hydrophobicity, humic substances, SOC and crop yield were compared after the application of different amounts of straw returns in the field, and the contribution of straw application in enhancing HA hydrophobicity was examined. The treatments included no straw application and soil stirring, no straw application with soil stirring, application of half-amount straw shallow-mixed field return, application of full-amount straw shallow-mixed field return and application of double-amount straw shallow-mixed field return. Using elemental analysis, infrared spectroscopy and fluorescence spectroscopy, the structural hydrophobicity of soil HA was exhaustively characterised. The results showed that the hydrogen to carbon ratio of HA increased by 11.46%, the ratio of hydrophobic to hydrophilic intensity increased by 21.02%, and the ratio of peak B to peak A fluorescence intensity decreased by 32.21% after 5 years of full amount straw shallow-mixing field return compared to no straw application and soil stirring. The observed results indicate that the augmentation in hydrophobicity stimulates the formation of HA, enhances soil humification, elevates SOC content by 9.78% and potentially contributes to the ultimate crop yield increase by 22.98%. Compared with stirring the soil, the contribution rate of applying full amount of straw to increase HA hydrophobicity was 49.57-62.05%, and the contribution rate to increase SOC and yield were 54.59% and 76.37%, respectively. While stirring the soil contributed to increasing hydrophobicity, straw application persisted as the primary factor in enhancing hydrophobicity. The findings of this study have significant implications for understanding the mechanism by which straw improves HA hydrophobicity, thereby facilitating carbon sequestration and increasing crop yield.

A Typology and Lead Isotope and Cultural Exchange Study on Bronze Knives from Shuangyuan Cemetery, Chengdu City, Southwest China

Background: Bronze knives, which have been excavated in large quantities and acquired hierarchical significance, are essential artifacts in Shu State in Southwest China. Building upon previous typological analyses of bronze knives, it is hypothesized that Shu culture may have imported foreign-style bronze knives. However, further demonstration of the provenance of metal materials, the typology of knives, and the cultural exchange necessitates a comprehensive examination through the lens of scientific analysis. The purpose of this study is to investigate the differences in the manufacturing processes and metal resources of Shu bronze knives with various cultural styles and whether bronze knives in the foreign styles were imported or locally imitated. Methods: In this study, the typology, portable X-ray fluorescence spectrometry and multi-collector inductively coupled plasma mass spectrometry were used to analyze twenty-four bronze knives unearthed from Shuangyuan cemetery, a cemetery of the Eastern Zhou Dynasty in Chengdu City, Sichuan Province, Southwest China. Results: The results of the study show that the knives of Shuangyuan Cemetery can be classified typologically into five types, encompassing both local and foreign styles. The predominant alloy composition of these knives is lead-tin bronze, characterized by a notably high tin content. Lead isotope ratios indicate that metal materials from the South China geochemical province and Yangtze geochemical province were mainly used to manufacture the bronze knives unearthed from the Shu state Conclusion: While the majority of foreign-style knives with ring-shaped heads were likely imported from neighboring regions like Chu state, distinctively styled type D and type E bronze knives appear to have been locally imitated by the Shu, showcasing a blend of external influences and indigenous innovation. The combination of typology and scientific analysis of the bronze knife may shed new light on the study of the Shu culture of the Eastern Zhou period.

Assessing statistical neural networks potentiality to distinguish PDO Kalamata and Molaoi olive oil varieties

Several regional areas in Greece produce high quality olive oil by cultivating certain varieties. Olive oil varieties of Kalamata and Molaoi are of special interest, since they produce extra virgin olive oil. Concretely, Kalamata is a city located in southwestern Greece. Intuitively, Molaoi is a town located in southeastern Greece. Subsequently, both geographic locations are known for their famous olive oil quality. Continually, Protected Designation of Origin (PDO) Kalamata olive oil, established by Council regulation (EC) No 510/2006, is considered an exceptional extra virgin olive oil variety. Specifically, there is a need to distinguish PDO Kalamata olive oil from other olive oil varieties is Greece such as the Molaoi olive oil, since PDO Kalamata olive oil is the main variety exported in the global olive oil market. Distinguishing PDO Kalamata from Molaoi olive oil is possible by incorporating statistical neural networks. Concretely, applying neural network experimentation enables differentiation between variations of certain chemical characteristics observed in certain geographic locations of Greece. In this paper, we use statistical neural networks to distinguish the geographical origin of PDO Kalamata olive oil compared with Molaoi olive oil based on synchronous excitation−emission fluorescence spectroscopy of provided olive oils samples evaluated in the chemical laboratory. Evaluation based on certain experimentation phase and subsequent data visualization of the adopted statistical neural networks are promising for distinguishing the samples of PDO Kalamata olive oil with high values of prediction accuracy. Such ability enables olive oil industry to assess extra virgin olive oil profitable potentiality in global market.

Modulation of the Microstructure and Enhancement of the Photocatalytic Performance of g-C3N4 by Thermal Exfoliation

This work explores the impact of reaction temperature during thermal exfoliation treatment of bulk-g-C3N4 in the air atmosphere on the structure and performance of the resulting CN photocatalyst. The analysis conducted using XRD, FT-IR, XPS, SEM, and elements mapping tests, illustrated an increase in nitrogen-vacancy and oxygen content on the surface of the CN photocatalyst, resulting in a porous and sparse structure, changes in crystal size, and improved visible light absorption performance. The photocatalytic reduction experiments of hexavalent chromium (Cr(VI)) showed that the CN-540 showed the highest reduction rate of 96.9%, with a reaction rate constant 6.21 times that of bulk-g-C3N4. After 100 min of illumination, the photocatalytic degradation rates of CN-540 for TC-HCl and RhB were 66.7% and 60.6%, respectively. The TOC test results indicated mineralization rates of 51.5% for TC-HCl and 46.6% for RhB. Room temperature fluorescence spectroscopy (PL), transient photocurrent response (TPC), and electrochemical impedance spectroscopy (EIS) measurements confirmed the excellent photogenerated charge carrier separation and transport efficiency of CN-540. The photocatalytic mechanism for reducing Cr(VI) by CN-540 was elucidated based on the active species •OH and •O2– and Mott-Schottky (M-S) tests. This study provides experimental data for optimizing the photocatalytic performance of g-C3N4 and paves a new way for developing efficient photocatalysts. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Heat-resistant concretes based on cement binders and waste from the metallurgical industry

The main direction of the development of heat-resistant concrete production is the use of new materials, ensuring mechanization and industrialization of construction, increasing the performance characteristics of refractory compositions, reducing material consumption, introducing waste-free technologies in the production of concrete with increased physical and mechanical characteristics under prolonged exposure to high temperatures on cement binders and waste from the metallurgical industry and reducing environmental pollution. A significant environmental impact on the environment is exerted by large-tonnage technogenic waste produced by JSC «Aluminum of Kazakhstan» – bauxite sludge obtained by processing bauxite into alumina containing 42.7% Fe2O3. The prospects of its application as a filler in heat-resistant concretes are considered, which makes it possible to increase the physico-mechanical and thermal characteristics. The composition and properties of this waste and the change in the properties of heat-resistant concrete during the introduction of filler have been studied. Reactive alumina has been studied, which is 99.9% submicron alumina with a very low content of Na2O oxide. It is shown that the properties of concrete change after the introduction of iron-containing waste in the amount of 5% and reactive alumina – 37.5% and 38.8%. Their volumetric weight, control strength, and other properties are increased. The improvement of physical, mechanical, and thermal characteristics depends on the structure and neoplasms in the obtained samples. Samples of heat-resistant concrete were analyzed using electron probe X-ray spectral qualitative and quantitative microanalysis and X-ray fluorescence spectrometry and it was shown that the iron-alumina waste contributes to the compaction of the structure due to its resistance to delamination and has increased fluidity at low humidity in the cementing mass. For further investigation of the physical-thermal characteristics, depending on the structure and neoplasms in the obtained samples, a petrographic method using a polarization microscope in transmitted and reflected light is required.

Synthesis of an Insulated Oligo(phenylene ethynylene) Dimer Through Cyclodextrin-Based [c2]Daisy Chain Rotaxane

Oligo(phenylene ethynylene)s (OPEs) are π-conjugated systems with promising optical, bioactive, and electrical properties, making them valuable candidates for molecular electronics and biosensors. Controlling the arrangement and orientation of π-conjugated systems is crucial in developing molecular devices. Recently, we developed insulated diarylacetylene dimers using a [c2]daisy chain rotaxane strategy, which brings two cores into close proximity without covalent bonding and shields them with permethylated α-cyclodextrins. Here, we synthesized an insulated OPE dimer using a similar rotaxane strategy to investigate its optical properties. The rotaxane structure and optical properties were evaluated using nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization high-resolution mass spectrometry (ESI-HRMS), and absorption and fluorescence spectroscopy. This study is expected to contribute to the development of optical and electronic materials utilizing OPEs.

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

We report the synthesis of polycyclic uracil derivatives. The method is based on palladium-catalysed Sonogashira–Hagihara and Suzuki–Miyaura cross-coupling reactions followed by Brønsted acid-mediated cycloisomerisation. The developed methodology tolerates various functional groups and leads to moderate up to quantitative yields of the final products. The impact of different functional groups on the optical properties was studied by UV–vis and fluorescence spectroscopy.

Long-range enhancement for fluorescence and Raman spectroscopy using Ag nanoislands protected with column-structured silica overlayer

We demonstrate long-range enhancement of fluorescence and Raman scattering using a dense random array of Ag nanoislands (AgNIs) coated with column-structured silica (CSS) overlayer of over 100 nm thickness, namely, remote plasmonic-like enhancement (RPE). The CSS layer provides physical and chemical protection, reducing the impact between analyte molecules and metal nanostructures. RPE plates are fabricated with high productivity using sputtering and chemical immersion in gold(I)/halide solution. The RPE plate significantly enhances Raman scattering and fluorescence, even without proximity between analyte molecules and metal nanostructures. The maximum enhancement factors are 107-fold for Raman scattering and 102-fold for fluorescence. RPE is successfully applied to enhance fluorescence biosensing of intracellular signalling dynamics in HeLa cells and Raman histological imaging of oesophagus tissues. Our findings present an interesting deviation from the conventional near-field enhancement theory, as they cannot be readily explained within its framework. However, based on the phenomenological aspects we have demonstrated, the observed enhancement is likely associated with the remote resonant coupling between the localised surface plasmon of AgNIs and the molecular transition dipole of the analyte, facilitated through the CSS structure. Although further investigation is warranted to fully understand the underlying mechanisms, the RPE plate offers practical advantages, such as high productivity and biocompatibility, making it a valuable tool for biosensing and biomolecular analysis in chemistry, biology, and medicine. We anticipate that RPE will advance as a versatile analytical tool for enhanced biosensing using Raman and fluorescence analysis in various biological contexts.

Energy Dispersive X-Ray Fluorescence Spectrometry Using a Matrix Corrected Fundamental Parameters Algorithm vs. Acid Digestion with ICP-AES: A Comparison of Two Methods for Soil Elemental Analysis

ABSTRACT Energy dispersive X-ray fluorescence spectrometry (ED-XRF) is evaluated as an alternative to conventional acid-mediated soil digestion methods for analysis of aluminum (Al), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), silicon (Si), strontium (Sr), titanium (Ti), and zirconium (Zr). The Kellogg Soil Survey Laboratory (KSSL) currently uses microwave-assisted digestion with inductively coupled plasma – atomic emission spectrometry (ICP-AES) to measure the 12 elements (Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Sr, Ti, Zr). The equipment needed to conduct the digestion method is expensive, the materials are hazardous, and the method is laborious. The Kellogg Soil Survey Laboratory (KSSL) has observed variable elemental recoveries for certain elements. The objective of the study was to evaluate an ED-XRF method as an alternative to the KSSL digestion method. The literature offers few examples of X-ray fluorescence (XRF) method development and validation. The candidate ED-XRF method offered a more efficient, less expensive, and less hazardous approach for measuring the 12 elements. Relative to the digestion method, the candidate ED-XRF method showed improved precision and accuracy for specific elements.

Spectroscopic Investigation of the Quadruplex DNA‐Binding Properties of 9‐Aryl‐Substituted Isoquinolinium Derivatives

AbstractThe spectroscopic investigation of the binding properties of berberine‐type 9‐aryl‐substituted isoquinolinium derivatives with G‐quadruplex DNA (G4‐DNA) are presented. Photometric titrations show that these ligands bind with high affinity to the telomeric G4‐DNA form 22AG (K=1.0–44×105 M−2). Furthermore, fluorimetric analysis of thermal DNA denaturation (FRET melting) reveals a significant thermal stabilization of G4‐DNA 22AG upon association with the methoxy‐substituted derivatives. As an analytically useful property, the derivatives with a phenyl substituent or with additional electron‐donating groups show a very weak fluorescence intensity, which increased significantly upon G4‐DNA complexation (fluorescence light‐up effect). Additional time‐resolved fluorescence spectroscopy indicated increased fluorescence lifetimes of the DNA‐bound 9‐(4‐methoxyphenyl)‐substituted derivative, when interacting with the quadruplex‐forming strand 22AG. Notably, the changes of the steady‐state and time‐resolved emission properties of the ligand are more pronounced with G4‐DNA than with duplex DNA so that the combination of these complementary methods may be used for the selective G4‐DNA detection.

Preferential Binding of Cations Modulates Electrostatically Driven Protein Aggregation and Disaggregation.

Protein aggregation resulting in either ordered amyloids or amorphous aggregates is not only restricted to deadly human diseases but also associated with biotechnological challenges encountered in the therapeutic and food industries. Elucidating the key structural determinants of protein aggregation is important to devise targeted inhibitory strategies, but it still remains a formidable task owing to the underlying hierarchy, stochasticity, and complexity associated with the self-assembly processes. Additionally, alterations in solution pH, salt types, and ionic strength modulate various noncovalent interactions, thus affecting the protein aggregation propensity and the aggregation kinetics. However, the molecular origin and a detailed understanding of the effects of weakly and strongly hydrated salts on protein aggregation and their plausible roles in the dissolution of aggregates remain elusive. In this study, using fluorescence and circular dichroism spectroscopy in combination with electron microscopy and light scattering techniques, we show that the ionic size, valency, and extent of hydration of cations play a crucial role in regulating the protein aggregation and disaggregation processes, which may elicit unique methods for governing the balance between protein self-assembly and disassembly.

An Increase in The Cross-Section of Two-Photon Absorption of Styrene Dye in Supramolecular Complexes with Cucurbituriles

Two-photon absorption cross sections of aqueous solutions of the styryl dye trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide (DASPI) and its inclusion complexes with cucurbit[n]urils (CB[n] n = 6–8) were measured using fluorescence spectroscopy. A nonmonotonic dependence of the cross-section size on the excitation wavelength and on the cavitand cavity size was found. Compared with a free dye, a sevenfold increase in the two-photon absorption cross section was observed in DASPI inclusion complexes with CB[8] at an excitation wavelength of 980 nm.

3D Fluorescence Spectroscopy Combined With Chemometrics as a Tool for Control of Imprinted Protein Purification From Template Molecules

ABSTRACTImprinted proteins (IPs) are promising alternatives to natural recognition systems, such as biological receptors or antibodies. One of the crucial stages during development of IPs is removal of the template molecules from its complex with the protein. In this study, bovine serum albumin was imprinted in the presence of 4‐hydroxycoumarin (4‐HC); purification of IPs were carried out by dialysis, and fluorescence 3D spectroscopy was used to monitor the IP purification process. Excitation–emission matrix (EEM) was further investigated via several chemometric algorithms (principal component analysis [PCA], parallel factor analysis [PARAFAC], and independent components analysis [ICA]). We found that the models using PARAFAC and ICA worked better than those of PCA. It was shown that PARAFAC and ICA analyses allow not only to recognize IP sample with signal close to nonimprinted protein, but also to provide recommendations on the optimal dialysis time.

Simultaneous adsorption of ammonia nitrogen and phosphate on electro-assisted magnesium/aluminum-loaded sludge-based biochar and its utilization as a plant fertilizer.

Herein, Mg/Al-loaded sludge-based biochar was prepared via electro-assisted impregnation. The structure and chemical analysis of modified sludge-based biochar (MgSBC-0.5(@Al) showed that the material was loaded with MgO and Al2O3. The specific surface area of MgSBC-0.5(@Al) was 11.27 times higher than that of unmodified sludge-based biochar (SBC). The simultaneous adsorption performance of MgSBC-0.5(@Al for ammonia nitrogen (NH4+-N) and phosphate phosphorus (PO43--P) was studied. The maximum adsorption capacities of MgSBC-0.5(@Al for NH4+-N and PO43--P at 298 K were 65.19 and 92.10 mg·g-1, respectively, 4.45 and 6.28 times higher than those of SBC. The external and internal elemental compositions of the modified and unmodified biochar specimens were quantitatively characterized using inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, and X-ray fluorescence spectrometry. The results emphasized the importance of Mg-loading for NH4+-N and PO43--P capture. MgO was mainly loaded on the surface of biochar, enabling adsorption through chemical reactions. Analysis showed that the adsorption of NH4+-N and PO43--P on the modified biochar proceeded simultaneously through multiple mechanisms. Particularly, the adsorption of NH4+-N and PO43--P occurred through the precipitation of struvite and physical adsorption, with PO43--P also adsorbed through the formation of MgHPO4 and CaHPO4. Other data indicated that Al, Ca, and Fe had a trapping effect on the adsorbate. Importantly, the biochar after adsorption could be used as a soil amendment.

Single-Particle Fluorescence Spectroscopy for Elucidating Charge Transfer and Catalytic Mechanisms on Nanophotocatalysts.

Photocatalysis is a cost-effective approach to producing renewable energy. A thorough comprehension of carrier separation at the micronano level is crucial for enhancing the photochemical conversion capabilities of photocatalysts. However, the heterogeneity of photocatalyst nanoparticles and complex charge migration processes limit the profound understanding of photocatalytic reaction mechanisms. By establishing the precise interrelationship between microscopic properties and photophysical behaviors of photocatalysts, single-particle fluorescence spectroscopy can elucidate the carrier separation and catalytic mechanism of the photocatalysts in situ, which provides perspectives for improving the photocatalytic efficiency. This Review primarily focuses on the basic principles and advantages of single-particle fluorescence spectroscopy and its progress in the study of plasmonic and semiconductor photocatalysis, especially emphasizing its importance in understanding the charge separation and photocatalytic reaction mechanism, which offers scientific guidance for designing efficient photocatalytic systems. Finally, we summarize and forecast the future development prospects of single-particle fluorescence spectroscopy technology, especially the insights into its technological upgrading.

Unusual Composition of the Sarezzano Reliquary Busts

The interdisciplinary study of two reliquary busts from Sarezzano (Piedmont, Italy) is a perfect example of the necessity to provide for material characterisation as a recurring common practice in historical studies and a mandatory step in conservation assessment. Furthermore, the diagnostics of cultural heritage play a crucial role in art historical research, providing relevant information on artefacts’ genesis, production technology, and conservation history. The study of the materials of the reliquary busts was performed by non-invasive (portable X-ray fluorescence spectrometry) and micro-invasive (stereomicroscope, attenuated total reflection Fourier transform infrared spectroscopy and powder X-ray diffraction analysis) methods. According to the results, the busts were found to be made of a tin–lead alloy, a rather unusual material for mediaeval reliquary busts. Moreover, the outcome suggests that the busts were originally silvered, except for the hair and beard which are still gilded. The analysis reveals the use of colophony as an adhesive buffer layer on the busts’ alloy, as well as inside them, to favour the metal working process, since it is found as degraded residue. Finally, even the typology of alloy decay is defined. All this information has enabled us to determine the artistic technique and estimate the value and quality of the material employed. In addition, it has led to the correct choice of materials and methods to be adopted during the restoration, and therefore the usage of more suitable solvents and tools.

Aqueous phase transfer of near-infrared ZnCuInS2/ZnS quantum dots: Synthesis and characterization

Cadmium-free and NIR fluorescent QDs are promising candidates for bio-application. Thus, we present the synthesis of ternary ZnCuInS2/ZnS (ZCIS/ZnS) quantum dots (QDs) where the molar variation of Cu/Zn of the precursors was used to tune the optical and structural properties. QDs with Cu/Zn molar ratio of 2/1 passivated with ZnS exhibited the best optical properties. They showed dominant near-infrared photoluminescence (approx. 850 nm) and highest quantum yield (approx. 52 %, λexc = 500 nm). Therefore, they were further subject to modification to ensure their transfer to the aqueous phase and improve biocompatibility. For this, different functionalization approaches were used. The first method relied on encapsulation with polymers like PSMA (poly(styrene co-maleic anhydride)) and PMAO (poly(maleic anhydride-alt-1-octadecene) coupled with polyetheramine (JEFF; Jeffamine M-1000), and the second relied on hydrophilization with PMAO. Furthermore, we also applied a surface ligand exchange process using DHLA (dihydrolipoic acid) and polyethylene glycol (PEG)-appended DHLA. The comprehensive study indicated that ZnCuInS2/ZnS QDs functionalized with PMAO (ZnCuInS2/ZnS@PMO) exhibited the highest photoluminescence (PL QY) along with ensured high colloidal stability in aqueous media. Moreover, no noticeable deterioration of the photoluminescence profile was observed for all used functionalization approaches. However, a significant decrease in QY was observed for almost all functionalized QDs except those that were PMO-capped. The synthesized QDs were systematically characterized by transmission electron microscopy (TEM), powder X-ray diffraction (XRD), UV–Vis absorption spectroscopy, and fluorescence spectroscopy. Biological studies indicate that the obtained hydrophilic ZCIS QDs are biocompatible and localized intracellularly inside endosomes.

ИССЛЕДОВАНИЕ ВОЗНИКНОВЕНИЯ ПОЖАРА ОТ ВОСПЛАМЕНЕНИЯ И ВЗРЫВА ПАРОВОЗДУШНОЙ СМЕСИ ПРИ ПРОВЕДЕНИИ ГАЗОСВАРОЧНЫХ РАБОТ

Using the example of a real fire that occurred as a result of violations of fire safety requirements during gas welding operations, it is demonstrated how the combined use of instrumental and computational methods makes it possible to determine the cause of the fire. The nature of combustible substances has been determined by fluorescence spectroscopy, gas-liquid chromatography and infrared spectroscopy. Using mathematical calculations, the amount of combustible substances necessary for the formation of an explosive mixture was determined. It is demonstrated how a combination of physical-chemical research methods and computational methods, allows for the determining the causal relationship between gas welding operations and the aforementioned explosion.

Interactions between dissolved organic matter with different molecular weights and nonylphenol in surface water bodies

Dissolved organic matter (DOM) has a complex composition, which can interact with various pollutants and affect the removal of pollutants. Therefore, a thorough understanding of the interaction between the encccvironmental hormone nonylphenol (NP) and DOM is crucial for environmental impact and development. In this study, the interaction was investigated by means of excitation emission matrix (EEM) fluorescence spectroscopy, UV–Vis spectroscopy, FT-IR spectroscopy, nuclear magnetic resonance (NMR) and complex model analysis. The interaction between different MW DOM and NP was verified by the spectral characterization data. According to the characterization analysis, the main components of DOM in water samples were proteinoid (C1, C2, C4) with MW < 1 k Da, and their binding capacity (log Ka value) and binding site number (n) showed the maximum values (3.37, 3.24, 3.26; 0.81, 1.22, 0.52). For the humus like substance (C3) with larger molecular weight, the log Ka value and the number of binding points n increased with increasing molecular weight, and the maximum values were 3.13 and 0.31, respectively. It can be seen that low molecular weight proteins have strong binding ability and binding sites with NP, and high molecular weight humus also have strong binding ability. Overall, the interaction between DOM and NP has molecular weight dependence and heterogeneity. The purpose of this study is to deeply understand the interaction characteristics of different MW DOM with NP, and to provide theoretical support and reference for the study of the removal effects of NP pollutants.