Publications by authors named "Mehdi Dadmehr"

Quantum dot-based optical biosensors represent a significant advancement for detection of mycotoxins that are toxic secondary metabolites produced by fungi and pose serious health risk effects. This review highlights the importance of detection of filamentous fungi such as Aspergillus, Penicillium, Fusarium, Claviceps, and Alternaria in mycotoxin production, leading to contamination of agricultural products and subsequent health issues. Conventional detection methods such as thin-layer chromatography, high-performance liquid chromatography, gas chromatography, and enzyme-linked immunosorbent assay are discussed with their respective advantages and limitations.

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The rapid and accurate detection of pathogens is crucial for effective disease prevention and management in healthcare, food safety, and environmental monitoring. While conventional pathogen detection methods like culture-based techniques and PCR are sensitive and selective, they are often time-consuming, require skilled operators, and are not suitable for point-of-care or on-site testing. To address these limitations, innovative sensor technologies have emerged that leverage the unique properties of nanomaterials.

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In the present study, encapsulation of Lactiplantibacillus plantarum (L.p) was performed using chitosan and casein through calcium phosphate intercrossing. Chitosan and casein both considered as non-toxic and biocompatible food derived components with intrinsic antioxidant properties.

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Background: Aflatoxin B1 (AFB1), is a potent hepatic carcinogen which causes cancer by inducing DNA changes in the liver cells. Variety of methods have been developed for detection of AFB1 which are based on single mode detection strategy. Fabrication of novel platform which are compatible for multimodal detection of AFB1 provide robust performance for reliable detection of AFB1.

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Urea is a common milk adulterant that falsely increases its protein content. Excessive consumption of urea is harmful to the kidney, liver, and gastrointestinal system. The conventional methods for urea detection in milk are time-consuming, costly, and require highly skilled operators.

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Corona Virus Disease 2019 (COVID-19) as the infectious disease caused the pandemic disease around the world through infection by SARS-CoV-2 virus. The common diagnosis approach is Quantitative RT-PCR (qRT-PCR) which is time consuming and labor intensive. In the present study a novel colorimetric aptasensor was developed based on intrinsic catalytic activity of chitosan film embedded with ZnO/CNT (ChF/ZnO/CNT) on 3,3',5,5'-tetramethylbenzidine (TMB) substrate.

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Matrix metalloproteinase (MMPs) are proteolytic enzymes which considered as important enzymes and their higher expression is associated with some malignant progression. In the present study, a novel and sensitive method was developed for detection of MMP-9 based on its gelatinase activity. Green emitting gold nanoclusters (AuNCs) has been synthesized by gelatin substrate and then AuNPs@gelatin/AuNCs nanocomposite structure were prepared through coating of gold nanoparticles (AuNPs) with gelatin/AuNCs.

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Aflatoxin as the potent carcinogenic mycotoxin had been received great attention for detection in food industry and safety. Due to low quantity of aflatoxin in food samples, there is a need to develop a sensitive method toward its detection. In the present study, an aflatoxin B1 (AFB1) specific aptasensor with internal complementary sequence was developed for detection of AFB1.

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Development of light-harvesting properties and inhibition of photogenerated charge carrier recombination are of paramount significance in the photocatalytic process. In the present work, we described the synthesis of core-shell heterostructures, which are composed of titanium oxide (TiO) and cerium oxide (CeO) deposited on a reduced graphene oxide (rGO) surface as a conductive substrate. Following the synthesis of ternary rGO-CeO@TiO and rGO-TiO@CeO nanostructures, their photocatalytic activity was investigated toward the degradation of rhodamine B dye as an organic pollutant under UV light irradiation.

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Erlotinib is a potent and highly specific tyrosine kinase inhibitor with the hindering effects on the growth of cancer cells. An electrochemical sensor with the great sensitivity and selectivity was fabricated for determining erlotinib by using a graphite rod electrode modified by the nitrogen-doped graphene quantum dots (N-GQDs) and a ternary nanohybrid comprising copper nanoparticles, polyaniline, along with graphene oxide (N-GQDs/CuNPs-PANI@GO) for the first time. The establishment of PANI and CuNPs was done simultaneously on the GO surface by theoxidative polymerization method.

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Phytase is the commercial enzyme for bioconversion of phytate substrate to digestible phosphate ions. Recently silver nanoclusters (AgNCs) have received great attention as the optical transducer nanoparticles in biosensors structure. The novel detection platform was developed to detect the phytase enzyme activity and phosphate ions based on fluorescence quenching of AgNCs.

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Presence of inorganic pollutants in water reservoirs is the treating factor for human health and environment. Semiconductor quantum dots (QDs) has been regarded as one of the most efficient nanoparticles for their enhanced photocatalytic activity. Medicinal plants are the safe sources to provide green template for biosynthesis of inorganic nanoparticles such as quantum dots.

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Developing a cheap, stable and effective photocatalyst is necessary for remediation of persistent organic pollutants. To address this challenge, we proposed a unique interfacial engineering technique and proper bandgap matching strategy to synthesize MWCNTs/ZnO/Chitosan ternary nanocomposite for effective photocatalytic application. The features of the prepared samples were determined by FESEM, TEM, EDX, elemental mapping, AFM, FT-IR, XRD, UV-Vis spectroscopy and BET surface analysis.

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A simple and sensitive method was developed for the detection of bacteria gelatinase activity based on their enzymatic hydrolysis effect on the surface plasmon resonance (SPR) of gelatin functionalized gold nanoparticles (Au@gelatin NPs) in bacteria supernatant. Characterization of synthesized NPs showed a very thin gelatin layer on the surface of about 20 nm AuNPs which modified the intrinsic SPR property of AuNPs. The extracted supernatants of applied bacteria were incubated with Au@gelatin NPs.

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Aflatoxin is regarded as the potent carcinogenic agent which is secreted from fungi and present in some food products. So far, many detection methods have been developed to determine the trace amounts of aflatoxin in foods. In the present study a colorimetric competitive assay for detection of aflatoxin B1 (AFB1) has been developed based on interaction of gelatin functionalized gold nanoparticles (AuNPs@gelatin) in specific enzymatic reaction.

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Methylation of DNA at carbon 5 of cytosines is the most common epigenetic modification of human genome. Due to its critical role in many normal cell processes such as growth and development, any aberrant methylation pattern in a particular locus may lead to abnormal functions and diseases such as cancer. Development of methods to detect methylation state of DNA which may eliminate labor-intensive chemical or enzymatic treatments has received considerable attention in recent years.

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DNA methylation mediated by DNA methyltransferase (MTase) enzyme is internal cell mechanism which regulate the expression or suppression of crucial genes involve in cancer early diagnosis. Herein, highly sensitive fluorescence biosensing platform was developed for monitoring of DNA Dam MTase enzyme activity and inhibition based on fluorescence signal on mechanism. The specific Au NP functionalized oligonucleotide probe with overhang end as a template for the synthesis of fluorescent silver nanoclusters (Ag NCs) was designed to provide the FRET occurrence.

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Abnormal expression of MicroRNA-21 (miRNA-21) is considered to be a reliable biomarker for the early diagnosis of cancer. In this work, a novel paper based biosensor was fabricated to detect sub-micro molar concentrations of miRNA-21 based on peroxidase mimetic activity of DNA-templated Ag/Pt nanoclusters (DNA-Ag/Pt NCs), which could catalyze the reaction of hydrogen peroxide and 3,3',5,5' tetramethylbenzidine (TMB), to produce a blue color. The Mechanism of reaction was based on the inhibition effect of miRNA-21 on peroxidase-like activity of nanosensor which resulted to quantitative determination of miRNA-21 concentration.

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Background: Boron Nitride Nanotubes (BNNTs) have recently emerged as an interesting field of study, because they could be used for the realization of developed, integrated and compact nanostructures to be formulated. BNNTs with similar surface morphology, alternating B and N atoms completely substitute for C atoms in a graphitic-like sheet with nearly no alterations in atomic spacing, with uniformity in dispersion in the solution, and readily applicable in biomedical applications with no obvious toxicity. Also demonstrating a good cell interaction and cell targeting.

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DNA methylation of cytosine bases, which is catalyzed by methyltransferase enzymes, involve biochemical processes that contribute to gene expression and gene regulation in cells. Detection of abnormal patterns of both methylated DNA and methyltransferase enzyme activity at early stages could be considered as promising targets for early cancer diagnosis. In the present study, a novel and facile method is introduced for the sensitive detection of the M.

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DNA methylation plays an important role in development process which contributes to genome stability and also regulates gene expression and gene silencing. Detection of genome regions with altered 5-methylcytosine distribution at a genome-wide scale is very important for early detection of gene silencing related diseases. In the present study as a continuation of studies on DNA methylation, the interactions between graphene quantum dots (GQDs) and unmethylated and methylated deoxyribonucleic acid (DNA) fragment were investigated.

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DNA methylation catalyzed by DNA methyl transferase (MTase) is a significant epigenetic process for modulating gene expression. Abnormal levels of DNA MTase enzyme have been regarded as a cancer biomarker or a sign of bacterial diseases. We developed a novel colorimetric method to assay M.

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DNA methylation entails the covalent addition of a methyl group to C-5 position of cytosine by a family of DNA methyltransferase enzymes and has a significant role in gene regulation. Epigenetic changes such as DNA methylation of CpG islands located in the promoter region of some tumor suppressor genes are very common in human diseases such as cancer. Detection of aberrant methylation pattern could serve as an excellent diagnostic approach.

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A novel sensitive method for detection of DNA methylation was developed with thioglycollic acid (TGA)-capped CdTe quantum dots (QDs) as fluorescence probes. Recognition of methylated DNA sites would be useful strategy due to the important roles of methylation in disease occurrence and developmental processes. DNA methylation occurs most often at cytosine-guanine sites (CpG dinucleotides) of gene promoters.

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Aflatoxins are potential food pollutants produced by fungi. Among them, Aflatoxin B1 (AFB1) is the most toxic. Therefore, a great deal of concern is associated with AFB1 toxicity.

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