Publications by authors named "Maliwan Amatatongchai"

The accumulation of oxidized low-density lipoprotein (oxLDL) in macrophages leads to the formation of foam cells and atherosclerosis development. Reducing the uptake of oxLDL in macrophages decreases the incidence and progression of atherosclerosis. Four distinct single-strand DNA sequences, namely, AP07, AP11, AP25, and AP29, were selected that demonstrated specific binding to distinct regions of oxidized apolipoprotein B100 (apoB100; the protein component of oxLDL) with low HDOCK scores.

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Background: Carcinoembryonic Antigen (CEA) and 4-nitroquinoline-N-oxide (4-NQO) are cancer markers that play a crucial role in tumor risk assessment and early cancer diagnosis. Therefore, it is in demand to develop a fast, accurate, simple, and cost-effective method to detect these cancer markers for quick and early stage-cancer diagnosis and treatment.

Results: Herein, we report a dual signaling approach for direct and indirect signal transduction of cancer biomarker binding on molecularly imprinted-electrodes integrated on an ePAD, enabling sensitive and selective quantitative analysis of 4-NQO and CEA.

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Oxidized low-density lipoprotein (oxLDL) induces the formation of atherosclerotic plaques. Apolipoprotein B100 (apoB100) is a crucial protein component in low-density lipoprotein (LDL), which includes oxLDL. The oxidation of amino acids and subsequent alterations in their structure generate oxLDL, which is a significant biomarker for the initial phases of coronary artery disease.

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A microscale colorimetric assay was designed and implemented for the simultaneous determination of clinical chemistry tests measuring six parameters, including glucose (GLU), total protein (TP), human serum albumin (HSA), uric acid (UA), total cholesterol (TC), and triglycerides (TGs) in plasma samples. The test kit was fabricated using chromogenic reagents, comprising specific enzymes and binding dyes. Multiple colors that appeared on the reaction well when it was exposed to each analyte were captured by a smartphone and processed by the homemade Check6 application, which was designed as a colorimetric analyzer and simultaneously generated a report that assessed test results against gender-dependent reference ranges.

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Article Synopsis
  • Measuring biomarkers VMA and 5-HIAA is important for diagnosing conditions like neuroblastoma, hypertension, and depression, among others.
  • The study presents new sensors made from graphene quantum dots (GQDs) coated with molecularly imprinted polymers designed to selectively detect both biomarkers simultaneously in urine and plasma.
  • The resulting Origami 3D electrochemical device offers enhanced sensitivity and selectivity for VMA and 5-HIAA, achieving impressive detection limits and wide dynamic ranges for effective clinical testing.
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We developed a novel, compact, three-dimensional electrochemical paper-based analytical device (3D-ePAD) for patulin (PT) determination. The selective and sensitive PT-imprinted Origami 3D-ePAD was constructed based on a graphene screen-printed electrode modified with manganese-zinc sulfide quantum dots coated with patulin imprinted polymer (Mn-ZnS QDs@PT-MIP/GSPE). The Mn-ZnS QDs@PT-MIP was synthesized using 2-oxindole as the template, methacrylic acid (MAA) as a monomer, N,N'-(1,2-dihydroxyethylene) bis (acrylamide) (DHEBA) as cross-linker and 2,2'-azobis (2-methylpropionitrile) (AIBN) as initiator, respectively.

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Herein, we present a novel Origami 3D-μPAD for colorimetric carbaryl detection using a super-efficient catalyst, namely mesoporous silica-platinum nanoparticles coated with a molecularly imprinted polymer (MSN-PtNPs@MIP). Morphological and structural characterization reveals that coating MIP on the MSN-PtNPs surface significantly increases the selective area, leading to larger numbers of imprinting sites for improved sensitivity and selectivity in determining carbaryl. The as-prepared MSN-PtNPs@MIP was used for catalytic oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by HO.

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Nanoscale imprinting significantly increases the specific surface area and recognition capabilities of a molecularly imprinted polymer by improving accessibility to analytes, binding kinetics, and template removal. Herein, we present a novel synthetic route for a dual molecularly imprinted polymer (dual-MIP) of the carcinogen oxidative stress biomarkers 3-nitrotyrosine (3-NT) and 4-nitroquinolin-N-oxide (4-NQO) as coatings on graphene quantum-dot capped gold nanoparticles (GQDs-AuNPs). The dual-MIP was successfully coated on the GQDs-AuNPs core via a (3-mercaptopropyl) trimethoxysilane (MPTMS) linkage and copolymerization with the 3-aminopropyltriethoxysilane (APTMS) functional monomer.

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Cadmium ion (Cd (II)) is a highly toxic heavy metal usually found in natural water. Exposure to Cd (II) can produce serious effects in human organs such as Itai-Itai disease. Therefore, the maximum allowance levels of Cd (II) in drinking water and herbal medicines imposed by the World Health Organization (WHO) are 3 μg L and 300 μg kg, respectively.

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We report a new ready-to-use sensor for simultaneous determination of paraquat (PQ) and glyphosate (GLY) based on a graphite screen-printed electrode modified with a dual-molecularly imprinted polymer coated on a mesoporous silica-platinum core. Amino-mesoporous silica nanoparticles (MSN-NH) were first synthesized by a simple co-condensation method using tetraethyl orthosilicate and 3-aminopropyltrimethoxysilane. PtNPs were then decorated on the surface of MSN-NH by chemical reduction.

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Article Synopsis
  • A novel dual-imprinted electrochemical paper-based analytical device (Di-ePAD) has been developed to simultaneously measure biomarkers 8-OHdG and 3-NT in urine and plasma samples, enhancing detection of oxidative stress.
  • The device utilizes a molecularly imprinted polymer (MIP) formed on a silica nanosphere decorated with silver nanoparticles, allowing for improved selectivity, conductivity, and catalytic activity in sensing analytes.
  • The Di-ePAD demonstrates a wide detection range (0.01-500 μM for 3-NT and 0.05-500 μM for 8-OHdG) with low detection limits and shows good accuracy in real sample analysis compared to traditional methods like HPLC.
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We propose the fabrication of a novel ready-to-use electrochemical sensor based on a screen-printed graphene paste electrode (SPGrE) modified with platinum nanoparticles and coated with a molecularly imprinted polymer (PtNPs@MIP) for sensitive and cost-effective detection of paraquat (PQ) herbicide. Successive coating of the PtNPs surface with SiO and vinyl end-groups formed the PtNPs@MIP. Next, we terminated the vinyl groups with a molecularly imprinted polymer (MIP) shell.

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This work presents a simple hydrothermal synthesis of nitrogen-doped carbon dots (N-CDs), fabrication of microfluidic paper-based analytical device (μPAD), and their joint application for colorimetric determination of total cholesterol (TC) in human blood. The N-CDs were characterized by various techniques including transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRD), and the optical and electronic properties of computational models were studied using the time-dependent density functional theory (TD-DFT). The characterization results confirmed the successful doping of nitrogen on the surface of carbon dots.

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We report a novel three-dimensional microfluidic paper-based analytical device (3D-μPAD) with colorimetric detection, using Mn-ZnS quantum dot embedded molecularly imprinted polymer (Mn-ZnS QD-MIP), for selective glyphosate determination in whole grain samples. Detection is based on the catalytic activity of Mn-ZnS QD-MIP in the HO oxidation of ABTS. Glyphosate imprinted polymer is successfully synthesized on the Mn-ZnS QD surface using a poly (N-isopropylacrylamide) (NIPAM) and N, N'-Methylenebisacrylamide (MBA) as the functional monomers.

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This work presents the development and application of a novel analytical approach for the determination of acid and base concentrations by titration using a microfluidic thread-based analytical device (μTAD). This approach proved to be a simple to fabricate and to use, high precision, and cost-efficient means of acid-base quantification. The μTAD was fabricated by immobilizing the untreated cotton threads onto a wood frame, followed by pre-coating with an indicator (20 μL) and a primary standard solution (3 μL), and was tested using real samples including drug, food, and household products where 3 μL of each sample was dropped onto the center of a thread.

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Article Synopsis
  • Salbutamol (SAL) is a substance harmful to human health and is banned as a growth promoter in livestock, prompting the need for its detection in meat and urine.
  • Researchers developed a competitive paper-based colorimetric immunoassay (PCI) using an Ag PO /Ag nanocomposite, which simplifies and cheapens the detection process while being sensitive and specific for SAL.
  • This new method is easy to fabricate with low-cost materials and requires only small amounts of samples and reagents, making it quicker and more efficient than traditional ELISA tests.
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This work reports the first use of cis-1,4-polyisoprene obtained from rubber latex (RL) waste as the hydrophobic reagent for the fabrication of a microfluidic paper-based analytical device (μPAD), providing a user-friendly means for magnesium detection. The μPAD was fabricated using a screen printing technique and the barcode-like paper sensor was then used for the detection of Mg(II) ions in RL and water samples. Using different types of paper media (paper towel, Whatman No.

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Article Synopsis
  • Researchers developed a new sensor for detecting creatinine that uses copper oxide nanoparticles coated with a specialized polymer, enhancing sensitivity and response time.
  • The sensor (CuO@MIP/CPE) shows strong electro-oxidation performance for creatinine detection, achieving a linear response from 0.5 to 200 μM and a low detection limit of 0.083 μM.
  • It successfully detected creatinine in human urine samples, with good precision and minimal performance loss when stored properly.
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Herein, we propose a highly sensitive and selective three-dimensional electrochemical paper-based analytical device (3D-ePAD) to determine serotonin (Ser). It uses a graphite-paste electrode modified with nanoparticles coated with molecularly imprinted polymer (MIP). FeO@Au nanoparticles were encapsulated with silica to create novel nano-sized MIP.

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A simple flow injection analysis (FIA) integrating with a metal-free approach for total antioxidant capacity (TAC) was developed. The non-toxic reaction was based on generating a vibrant blue radical from imipramine to avoid the potential interferents arising from the colorful fruit extracts. The blue radical can be rapidly scavenged by antioxidant compounds present in the sample.

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A new and facile method for selective measurement of profenofos (PFF) using a simple flow-injection system with a molecularly-imprinted-polymer-coated carbon nanotube (3D-CNTs@MIP) amperometric sensor is proposed. The 3D-CNTs@MIP was synthesized by successively coating the surface of carboxylated CNTs with SiO and vinyl end groups, then terminating with molecularly imprinted polymer (MIP) shells. MIP was grafted to the CNT cores using methacrylic acid (MAA) monomer, ethylene glycol dimethacrylate (EGDMA) as cross linker, and 2,2'-azobisisobutyronitrile (AIBN) as initiator.

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This work describes analytical approaches based on simple complexometric and argentometric titrations leading to the color change of a novel microfluidic thread-based analytical device (µTAD). The device was fabricated from a cotton thread (15 cm) treated with indicator solution, providing an easy-to-use platform for rapid measurement of analyte concentration in aqueous solution. The thread was immobilized onto a support, being a polypropylene sheet or box platform, to facilitate loading of liquid samples.

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A smartphone application, called CAnal, was developed as a colorimetric analyzer in paper-based devices for sensitive and selective determination of mercury(II) in water samples. Measurement on the double layer of a microfluidic paper-based analytical device (μPAD) fabricated by alkyl ketene dimer (AKD)-inkjet printing technique with special design doped with unmodified silver nanoparticles (AgNPs) onto the detection zones was performed by monitoring the gray intensity in the blue channel of AgNPs, which disintegrated when exposed to mercury(II) on μPAD. Under the optimized conditions, the developed approach showed high sensitivity, low limit of detection (0.

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Herein, we propose a new approach for selective determination of carbofuran (CBF) in vegetables, based on a simple flow-injection system using a molecularly-imprinted amperometric sensor. The sensor design is based on a carbon-paste electrode decorated with carbon nanotubes and gold-coated magnetite (CNTs-FeO@Au/CPE) coated with a molecularly-imprinted polymer (MIP) for CBF sensing. The MIP was synthesized on the electrode surface by electropolymerization using a supramolecular complex, namely 4-ter-butylcalix [8] arene-CBF (4TB[8]A-CBF), as the template.

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We report a novel amperometric glucose biosensor based on glucose oxidase (GOx) immobilized on a carbon nanotube (CNTs)-poly(diallyldimethyl-ammonium chloride) (PDDA)-platinum nanoparticle (PtNPs) modified carbon-paste electrode (CNTs-PDDA-PtNPs/CPE). The CNTs-PDDA-PtNPs composite materials were characterized by TEM and electrochemical techniques. Cyclic voltammetric results reveal direct electron transfer of the immobilized GOx, indicated by two quasi-reversible redox peaks at a potential of 0.

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