Low Molecular Weight Compounds Research Articles

Molecular simulation of CH4 and CO2 adsorption behavior in coal physicochemical structure model and its control mechanism

In order to clarify the microscopic coupling mechanism among chemical composition and structure, nanopores and gas adsorption, this study used molecular simulation to investigate the adsorption behavior of CH4 and CO2 molecules in different coal physicochemical structure models under various environment conditions. The results show that with the dissolution of low molecular weight compounds (LMWCs), the absolute adsorption capacity for CO2 and CH4 in aromatic pores gradually increases, and slit pores show a more obvious promotional effect on gas adsorption. On the other hand, observing the radial distribution function(RDF) between the main functional groups in coal and CH4/CO2, oxygen-containing functional groups and aromatic structures display a significant impact on the distribution of gas molecules on coal surface, especially –COOH and -O- groups. While free LMWCs are easy to generate competitive adsorption with gas molecules. Further, on the basis of adsorption heat and energy changes in coal-gas system, it concludes that CH4 molecules on the coal surface always keep physical adsorption, but CO2 molecules are dominated by physical adsorption with weak chemical adsorption. Finally, the relationship among chemical composition and structure, nanopores and gas adsorption is established to reveal the microscopic coupling effect during gas adsorption.

Effect of Hyaluronic Acid on the Self-Assembly of a Dipeptide-Based Supramolecular Gel.

The combination of polymers and low molecular weight (LMW) compounds is a powerful approach to prepare new supramolecular materials. Here we prepare two-component hydrogels made by a well-known and biologically active polymer, hyaluronic acid (HA), and a dipeptide-based supramolecular gelator. We undertake a detailed study of materials with different compositions including macroscopic (hydrogel formation, rheology) and micro/nanoscopic characterization (electron microscopy, X-ray powder diffraction). We observe that the two components mutually benefit in the new materials: a minimum amount of HA helps to reduce the polymorphism of the LMW network leading to reproducible hydrogels with improved mechanical properties; the LMW component network holds HA without the need for an irreversible covalent crosslinking. These materials have a great potential for biomedical application as, for instance, extracellular matrix mimetics for cell growth. As a proof of concept, we have observed that this material is effective for cell growth in suspension and avoids cell sedimentation even in the presence of competing cell-adhesive surfaces. This may be of interest to advanced cell delivery techniques.

Composition, structural properties and immunomodulatory activity of several aqueous Pleurotus β-glucan-rich extracts

In this work, aqueous extracts from six different Pleurotus species were obtained and their yield, gross composition, β-glucan content, monosaccharide profile, thermal stability, molecular weight distribution, and FT-IR were analyzed before and after purification through ethanol precipitation of the carbohydrate-rich fractions. The bioactivity (anti-inflammatory and immunomodulatory activity) of the various fractions obtained was also analyzed in three different cell cultures and compared with a lentinan control. The trend observed after purification of the aqueous fractions was an increase in the concentration of polysaccharides (especially β-glucans), a decrease in ash, glucosamine and protein content and the elimination of low molecular weight (Mw) compounds, thus leaving in the purified samples high Mw populations with increased thermal stability. Interestingly, all these purified fractions displayed immunomodulatory capacity when tested in THP-1 macrophages and most of them also showed significant activity in HEK-hTLR4 cells, highlighting the bioactivity observed for Pleurotus ostreatus (both the extracts obtained from the whole mushroom and from the stipes). This specific species was richer in heteropolysaccharides, having moderate β-glucan content and being enriched upon purification in a high Mw fraction with good thermal stability.

Ultraviolet photodissociation and collision-induced dissociation for qualitative/quantitative analysis of low molecular weight compounds by liquid chromatography-mass spectrometry

Collision-induced dissociation (CID) is the most wildly used fragmentation technique for qualitative and quantitative determination of low molecular weight compounds (LMWC). Ultraviolet photodissociation (UVPD) has been mainly investigated for the analysis of peptides and lipids while only in a limited way for LMWC. A triple quadrupole linear ion trap instrument has been modified to allow ultraviolet photodissociation (UVPD) in the end of the q2 region enabling various workflows with and without data-dependent acquisition (DDA) combining CID and UVPD in the same LC–MS analysis. The performance of UVPD, with a 266-nm laser, is compared to CID for a mix of 90 molecules from different classes of LMWC including peptides, pesticides, pharmaceuticals, metabolites, and drugs of abuse. These two activation methods offer complementary fragments as well as common fragments with similar sensitivities for most analytes investigated. The versatility of UVPD and CID is also demonstrated for quantitative analysis in human plasma of bosentan and its desmethyl metabolite, used as model analytes. Different background signals are observed for both fragmentation methods as well as unique fragments which opens the possibility of developing a selective quantitative assay with improved sample throughput, in particular for analytes present in different matrices.Graphical

Stormwater discharge: An overlooked source of disinfection byproduct precursors

Discharge from the stormwater system is as an important pathway for contaminant transport, impacting the quantity and characteristics of dissolved organic matter (DOM) in surface water, and thus the formation of disinfection byproducts (DBPs) during downstream drinking water disinfection. In this study, DOM in stormwater pipes was characterized by size-exclusion chromatography, and the formation of 27 DBPs and halogen-specific total organic halogen (TOX) following chlorination was investigated. Overall, DOM in stormwater pipes was characterized by low molecular weight compounds and microbial-derived organics. Total DBP concentrations in chlorinated stormwaters were ∼1–15 times higher than in chlorinated surface waters. DBPs formed in stormwaters were dominated by trihalomethanes and haloacetic acids. Moreover, the DBP-associated toxicity of chlorinated stormwaters was ∼1–38 times higher than in chlorinated surface waters, and mainly due to the presence of large amount of haloacetaldehydes and haloacetonitriles. Sampling during a rainfall event suggested that stormwater discharge significantly increased DBP precursors in the surface water. The high formation and estimated toxicity of DBPs in stormwater discharge indicates this is an overlooked source of DBP precursors, posing a threat to the aquatic environment and potentially drinking water quality.

Rhizosphere and detritusphere habitats modulate expression of soil N-cycling genes during plant development.

Interactions between plant roots and rhizosphere bacteria modulate nitrogen (N)-cycling processes and create habitats rich in low molecular weight compounds (exudates) and complex organic molecules (decaying root litter) compared to those of bulk soil. Microbial N-cycling is regulated by edaphic conditions and genes from many interconnected metabolic pathways, but most studies of soil N-cycling gene expression have focused on single pathways. Currently, we lack a comprehensive understanding of the interplay between soil N-cycling gene regulation, spatial habitat, and time. We present results from a replicated time series of soil metatranscriptomes; we followed gene expression of multiple N transformations in four soil habitats (rhizosphere, detritusphere, rhizo-detritusphere, and bulk soil) during active root growth for the annual grass, Avena fatua. The presence of root litter and living roots significantly altered the trajectories of N-cycling gene expression. Upregulation of assimilatory nitrate reduction in the rhizosphere suggests that rhizosphere bacteria were actively competing with roots for nitrate. Simultaneously, ammonium assimilatory pathways were upregulated in both rhizosphere and detritusphere soil, which could have limited N availability to plants. The detritusphere supported dissimilatory processes DNRA and denitrification. Expression of nitrification genes was dominated by three phylotypes of Thaumarchaeota and was upregulated in bulk soil. Unidirectional ammonium assimilation and its regulatory genes (GS/GOGAT) were upregulated near relatively young roots and highly decayed root litter, suggesting N may have been limiting in these habitats (GS/GOGAT is typically activated under N limitation). Our comprehensive analysis indicates that differences in carbon and inorganic N availability control contemporaneous transcription of N-cycling pathways in soil habitats. IMPORTANCE Plant roots modulate microbial nitrogen (N) cycling by regulating the supply of root-derived carbon and nitrogen uptake. These differences in resource availability cause distinct micro-habitats to develop: soil near living roots, decaying roots, near both, or outside the direct influence of roots. While many environmental factors and genes control the microbial processes involved in the nitrogen cycle, most research has focused on single genes and pathways, neglecting the interactive effects these pathways have on each other. The processes controlled by these pathways determine consumption and production of N by soil microorganisms. We followed the expression of N-cycling genes in four soil microhabitats over a period of active root growth for an annual grass. We found that the presence of root litter and living roots significantly altered gene expression involved in multiple nitrogen pathways, as well as tradeoffs between pathways, which ultimately regulate N availability to plants.

4-Nitrocatechol as a novel matrix for low-molecular-weight compounds in situ detection and imaging in biological tissues by MALDI-MSI

Low-molecular-weight (LMW) compounds are ubiquitous in living organisms and play essential roles in biological processes. The direct analysis of LMW compounds in biological tissues by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) could provide a more comprehensive understanding of their essential functions. Here, we evaluated 4-nitrocatechol (4-NC) as a novel positive-ion matrix for enhancing in situ detection and imaging of LMW compounds from the rat liver, brain, and germinating Chinese-yew seed by MALDI-MS. Our results showed that the 4-NC possessed remarkable features, including strong ultraviolet absorption, uniform matrix crystal, excellent chemical stability, and fewer matrix-related background peaks. The use of 4-NC led to the successful detection of 232, 218, and 193 LMW compounds from the three abovementioned tissue sections, respectively. Also, the use of 4-NC improved the imaging quality of LMW compounds in tissue sections through MALDI-MSI and has the potential as a matrix for MALDI tissue imaging of LMW compounds.

Computational analysis of the interactions between Ebselen and derivatives with the active site of the main protease from SARS-CoV-2

The main protease (Mpro) of the novel coronavirus SARS-CoV-2 is a key target for developing antiviral drugs. Ebselen (EbSe) is a selenium-containing compound that has been shown to inhibit Mpro in vitro by forming a covalent bond with the cysteine (Cys) residue in the active site of the enzyme. However, EbSe can also bind to other proteins, like albumin, and low molecular weight compounds that have free thiol groups, such as Cys and glutathione (GSH), which may affect its availability and activity. In this study, we analyzed the Mpro interaction with EbSe, its analogues, and its metabolites with Cys, GSH, and albumin by molecular docking. We also simulated the electronic structure of the generated molecules by density functional theory (DFT) and explored the stability of EbSe and one of its best derivatives, EbSe-2,5-MeClPh, in the catalytic pocket of Mpro through covalent docking and molecular dynamics. Our results show that EbSe and its analogues bound to GSH/albumin have larger distance between the selenium atom of the ligands and the sulfur atom of Cys145 of Mpro than the other compounds. This suggests that EbSe and its GSH/albumin-analogues may have less affinity for the active site of Mpro. EbSe-2,5-MeClPh was found one of the best molecules, and in molecular dynamics simulations, it showed to undergo more conformational changes in the active site of Mpro, in relation to EbSe, which remained stable in the catalytic pocket. Moreover, this study also reveals that all compounds have the potential to interact closely with the active site of Mpro, providing us with a concept of which derivatives may be promising for in vitro analysis in the future. We propose that these compounds are potential covalent inhibitors of Mpro and that organoselenium compounds are molecules that should be studied for their antiviral properties.

High content of low molecular weight organics does not always affect pharmaceutical adsorption on activated carbon: The case of acetate, propionate and ethanol in source-separated urine

Adsorption on activated carbon is a common process to remove pharmaceuticals in wastewater treatment. Activated carbon adsorption is usually applied to wastewater with a low content of biological degradable organics, i.e. after biological treatment. Especially low molecular weight (LMW) compounds are known to compete with pharmaceuticals for adsorption sites. The goal of this study was to test the hypothesis that biological treatment is necessary for efficient pharmaceutical removal. Source-separated urine after anaerobic storage (anaerobically stored urine) and after aerobic biological removal of organics without nitrification (organics-depleted urine) were used in this study. In anaerobically stored urine 60% of the organic compounds were LMW organics, of which about 40% were acetate and propionate. 74% of the DOC and 100% of acetate and propionate were removed during aerobic biological treatment. To investigate the effect of the organic compounds on pharmaceutical removal, sorption experiments with 19 spiked pharmaceuticals and one artificial sweetener were conducted with powdered activated carbon. Ethanol, another LMW organic, was included in the study, as it is regularly used for pharmaceutical spiking thereby strongly increasing the DOC content. The experiments showed that the adsorption of the pharmaceuticals and the sweetener were hardly affected by the easily biodegradable LMW organics or ethanol. Therefore, it was concluded that biological pre-treatment is not necessary for efficient pharmaceutical adsorption. Since acetate, propionate and ethanol contribute substantially to the DOC content but do not absorb UV light, the latter is recommended as indicator for pharmaceutical removal in solutions with high contents of biodegradable LMW organics.

The Effect of Organic Matter from Sewage Sludge as an Interfacial Layer on the Surface of Nano-Al and Fluoride.

Due to its high reactivity, the nano aluminum particle (n-Al) has attracted more attention in energetic materials but is easily oxidized during processing. In order to realize sewage sludge (SS) resource and n-Al coating, the organic matter was extracted from SS, using the deep eutectic solvent method due to its strong dissolving capacity, and then the organic matter was pretreated by ball milling, which was used as an interfacial layer between n-Al and fluoride. It was found that organic matter was successfully extracted from SS. The main organic matter is proteins. The ball milling method can effectively destroy the secondary structure of proteins to release more active functional groups. During the pretreatment, the Maillard reaction broke the proteins structure to form more active low molecular weight compounds. It was confirmed that n-Al can be coated by PBSP under mild conditions to form a uniform core-shell structure. PFOA can effectively coat the n-Al@PBSP to form n-Al@PBSP/PFOA, which can enhance the combustion of n-Al. The gas phase flame temperature can notably improve to 2892 K. The reaction mechanism between n-Al and coating was analyzed. The results could help SS treatment and provide new insights for n-Al coating and SS-based organic matter recovery and utilization.

Aspects of the study on some aromatic species of the genus Agastache Gronov

The study has been focused on the field of introduction, conservation and use of aromatic and medicinal plants, which represent inexhaustible sources of raw materials for the pharmaceutical, cosmetic and food industries. The article describes the results of the evaluation of the prospects for the introduction of 4 species of the genus Agastache Gronov: Agastache foeniculum ( Pursh) Kuntze, Agastache rugosa (Fisch & C. A Mey.) O. Kuntze, Agastache urticifolia (Benth.) Kuntze, Agastache nepetoides L., species that have not been studied in much detail, but of high therapeutic value. The studies focused on the bio-ecological and phytochemical research on the plants, in order to highlight the biomorphological peculiarities, the essential oil content and the possibility of using them in various branches of the national economy. Far from being an exhausted source of remedies, natural products continue to provide low molecular weight compounds with important biological properties that can be used for pharmaceutical purposes.

Oxygen consumption and formation of recalcitrant organic carbon from the decomposition of free-floating macrophyte leachates.

Aquatic macrophytes contain high levels of hydrosoluble compounds. These compounds disproportionately support microbial breakdown and affect biological oxygen demand in eutrophic waters. In this study, we investigated the fate of leachates from free-floating macrophytes (Pistia stratiotes and Eichhornia crassipes) usually present in eutrophic tropical lacustrine environments. After extraction, the leachates were fractioned into high and low molecular weight compounds and incubated under aerobic conditions, in the dark and at 20.0 ± 1.3°C. The concentrations of dissolved oxygen and the total, dissolved, and particulate organic carbon (TOC, DOC, and POC) were determined during 60days. The selected leachates supported the detritus trophic chain of the Barra Bonita Reservoir. High rates of carbon transfer were measured, which were ascribed to the temperature selected (20°C), nutrient availability, and labile fractions of the leachates. Decomposition occurred mainly through catabolic pathways (mineralization), with the formation of POC (immobilization) being only minor. In the early stages of P. stratiotes and E. crassipes decomposition, the mineralization of leachates (mainly the low molecular weight) led to declines in dissolved oxygen. Owing to the low rates of mass loss, the recalcitrant fractions of these leachates should constitute the main forms of organic carbon exported from the reservoir.

A tandem of GC‐MS and electroanalysis for a rapid chemical profiling of bacterial extracellular matrix

AbstractHerein an assay toward a rapid and reliable profiling of extracellular matrix of Escherichia coli (E. coli) utilizing a tandem of GC‐MS as a tool for definition of the exact chemical nature of low molecular weight compounds and cyclic voltammetry for their high throughput detection is presented.Briefly, during a set of investigations the formation of glycerol in the extracellular matrix (ECM) of E. coli at physiological relevant conditions of cells was revealed. Based on the obtained knowledge, the electrochemical protocol allowing both qualitative and quantitative analyses of glycerol in E. coli ECMs at palladium ink‐modified screen printed electrodes with precision values (RSD) <10 % and recovery rates ranged from 98 % to 102 % was proposed.The provided protocol for a rapid electrochemical profiling of the bacterial ECMs can readily be used as a guideline for the controlled electroanalysis of target electroactive signaling analytes in complex biological samples.

Application of Alcohol-Salt Aqueous Biphasic System for the Recovery of Ectoine

Ectoine is an osmoregulatory compound synthesized by halophiles which has attracted attention in the biotechnology, pharmaceuticals, and cosmetics industries due to its stabilizing and protective properties. Conventional methods for ectoine recovery are complex, costly, and often result in low yields. Therefore, there is a growing interest in exploring simple and cost-effective strategies for ectoine recovery. The aqueous biphasic system (ABS) has been employed for the recovery and purification of numerous biocompounds, but the study of low-molecular weight compounds partitioning in ABS remains limited. This study aimed to investigate the feasibility of alcohol–salt ABS for ectoine recovery from Halomonas salina DSM5928T cells. The influences of types and compositions of phase-forming components, crude load concentration, pH, and adjuvants on ectoine recovery were evaluated. Results revealed that ectoine favoured partitioning into the salt-rich bottom phase of alcohol–salt ABS owing to its inherent hydrophilic characteristic. ABS consisting of 16% (w/w) 1-propanol, 20% (w/w) sulphate at pH 6.0, 30% (w/w) crude load, and 1% (w/w) sodium chloride resulted in a partition coefficient (KE) of 9.61 ± 0.05 and a yield (YB) of 97.50% ± 0.21. A purity (PE) of 86.73% was achieved with the 1-propanol-sulphate ABS. Alcohol–salt ABS proved to be an effective approach for ectoine recovery, meeting the raising market demand for industrial applications.

Exoproteomic Study and Transcriptional Responses of Laccase and Ligninolytic Peroxidase Genes of White-Rot Fungus Trametes hirsuta LE-BIN 072 Grown in the Presence of Monolignol-Related Phenolic Compounds.

Being an abundant renewable source of aromatic compounds, lignin is an important component of future bio-based economy. Currently, biotechnological processing of lignin through low molecular weight compounds is one of the conceptually promising ways for its valorization. To obtain lignin fragments suitable for further inclusion into microbial metabolism, it is proposed to use a ligninolytic system of white-rot fungi, which mainly comprises laccases and peroxidases. However, laccase and peroxidase genes are almost always represented by many non-allelic copies that form multigene families within the genome of white-rot fungi, and the contributions of exact family members to the overall process of lignin degradation has not yet been determined. In this article, the response of the Trametes hirsuta LE-BIN 072 ligninolytic system to the presence of various monolignol-related phenolic compounds (veratryl alcohol, p-coumaric acid, vanillic acid, and syringic acid) in culture media was monitored at the level of gene transcription and protein secretion. By showing which isozymes contribute to the overall functioning of the ligninolytic system of the T. hirsuta LE-BIN 072, the data obtained in this study will greatly contribute to the possible application of this fungus and its ligninolytic enzymes in lignin depolymerization processes.

Use of carbon-13 NMR to identify known natural products by querying a nuclear magnetic resonance database-An assessment.

The quick identification of known organic low molecular weight compounds, also known as structural dereplication, is a highly important task in the chemical profiling of natural resource extracts. To that end, a method that relies on carbon-13 nuclear magnetic resonance (NMR) spectroscopy, elaborated in earlier works of the author's research group, requires the availability of a dedicated database that establishes relationships between chemical structures, biological and chemical taxonomy, and spectroscopy. The construction of such a database, called acd_lotus, was reported earlier, and its usefulness was illustrated by only three examples. This article presents the results of structure searches carried out starting from 58 carbon-13 NMR data sets recorded on compounds selected in the metabolomics section of the biological magnetic resonance bank (BMRB). Two compound retrieval methods were employed. The first one involves searching in the acd_lotus database using commercial software. The second one operates through the freely accessible web interface of the nmrshiftdb2 database, which includes the compounds present in acd_lotus and many others. The two structural dereplication methods have proved to be efficient and can be used together in a complementary way.

Regulation on copper-tolerance in Citrus sinensis seedlings by boron addition: Insights from root exudates, related metabolism, and gene expression

Boron (B) can alleviate Citrus copper (Cu)-toxicity. However, the underlying mechanism by which B mitigates Cu-toxicity is unclear. ‘Xuegan’ (Citrus sinensis) seedlings were exposed to 0.5 (control) or 350 (Cu-toxicity) µM Cu and 2.5 or 25 µM B for 24 weeks. Thereafter, we investigated the secretion of low molecular weight compounds [LMWCs; citrate, malate, total soluble sugars (TSS), total phenolics (TP), and total free amino acids (TFAA)] by excised roots and their concentrations in roots and leaves, as well as related enzyme gene expression and activities in roots and leaves. Cu-stress stimulated root release of malate and TFAA, which might contribute to citrus Cu-tolerance. However, B-mediated-mitigation of Cu-stress could not be explained in this way, since B addition failed to further stimulate malate and TFAA secretion. Indeed, B addition decreased Cu-stimulated-secretion of malate. Further analysis suggested that Cu-induced-exudation of malate and TFAA was not regulated by their levels in roots. By contrast, B addition increased malate, citrate, and TFAA concentrations in Cu-toxic roots. Cu-toxicity increased TP concentration in 25 μM B-treated leaves, but not in 2.5 μM B-treated leaves. Our findings suggested that the internal detoxification of Cu by LMWCs played a role in B-mediated-alleviation of Cu-toxicity.

Modeling the Biocatalytic Method of Lipid Extraction Using Artificial Neural Networks

The paper presents the data on lipid fraction extraction from the raw fat of hibernating hunting animals. The processing of valuable raw materials must be maximized. For this purpose, various methods of rendering are used. As a result of temperature exposure, the protein part of raw fat undergoes significant changes. The protein denatures under the influence of temperature, and the dross formed during the rendering process absorbs and retains up to 30% of the fat. The authors propose using proteolytic enzyme preparations for a more complete extraction of fats, as the enzymes will hydrolyze the protein into compounds of lower molecular weight both before and during the rendering process. The experiment proved that the biocatalytic method allows achieving a fat yield of more than 95%. The best result can be obtained if the rendering is carried out at optimal parameters, which can be defined using a mathematical model. Mathematical modeling was carried out using an artificial neural network. During the study, a fully connected neural network was designed; it had eight hidden layers with 64 neurons in each, and its accuracy was measured by mean relative error, which amounted to 5.16%. With the help of the network, the optimal values of applied concentration, temperature and duration of rendering, at which a fat yield of more than 98% is achieved, were determined for each enzyme preparation. After that, the obtained values were confirmed experimentally. Thus, the study showed the efficiency of using artificial neural networks for modeling the biocatalytic method of lipid extraction.

Recent advances in lignins: fundamentals and applications

Lignin, one of the most abundant biopolymers on Earth, is a constant object of numerous fundamental and applied studies. Lignin processing is a challenging task of biorefining. Recent publications mainly concern various directions of valorization of technical lignins, as well as applications of lignin in medicine and pharmacology, 3D printing, synthesis of carbon fibres and biofuels. In the field of fundamental research, studies on lignin biosynthesis are of special attention. The review is devoted to the latest advances in the chemistry of lignin. The currently available data on the structure and biosynthesis of lignin are discussed. The trends in lignin valorization, such as pyrolysis and carbonation, production of composites, copolymers and nanoparticles, synthesis of practically valuable low-molecular-weight substances, production of hydro- and aerogels, <i>etc</i>., are analyzed in detail. It is noted that at present, the practical application of lignin is developing in two directions: valorization of technical lignins <i>per se</i>, without prior depolymerization, and valorization <i>via</i> low molecular weight compounds, mainly monomers, formed through lignin degradation by various methods.<br> The bibliography includes 130 references.

A comparative study for evaluating the binding affinity of MARAS-selected aptamer and a patented aptamer towards aflatoxin B1 by electrochemical impedimetric aptasensing

Magnetic-assisted rapid aptamer selection (MARAS) is a technique that uses magnetic nanoparticles to efficiently separate aptamer-target complexes under an alternating magnetic field, thereby reducing the time and number of selection rounds required. This study investigated the applicability of MARAS in selecting aptamers against a small molecule, aflatoxin B1 (AFB1). Among the six MARAS-selected aptamers, DNA 1 demonstrated the highest binding affinity. Its Kd value, further estimated from aptasensing data, was 43.7 nM, which is comparable to the Kd value of the patented aptamer (55.6 nM). The DNA 1-immobilized aptasensor exhibited good repeatability (RSD < 7 %, N = 3), linearity (R2 = 0.9613 from 1 to 100 nM), and a calculated LOD of 0.42 nM. Specificity testing indicated that interferences from ochratoxin A, aflatoxin B2, aflatoxin G1, and aflatoxin G2 were all below 7 %. The developed aptasensor was also applied to detect AFB1 content in the peanut sample matrix, achieving a good recovery rate ranging from 94.3 % to 112.2 %. Overall, this study confirms the potential of MARAS as a promising technique for identifying aptamers with strong binding affinities towards low molecular weight compounds such as AFB1. Additionally, the DNA 1-immobilized aptasensor provided a simple, accurate, and cost-effective alternative for AFB1 monitoring.