Phromyothin, Darinee

Preferred name

Alternative Name

Phromyothin, D.

Phromyothin, Darinee Sae Tang

Main Affiliation

Integrated Innovative Technology

darinee.ph@kmitl.ac.th

Now showing 1 - 10 of 24

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Electrochemical analysis of cypermethrin using a gold printed circuit board electrode modified with poly(methyl methacrylate)
(2019-01-01)
Leepheng, Piyawan
;
Phromyothin, Darinee
A gold printed circuit board (PCB) electrode modified with poly(methyl methacrylate) (PMMA) was studied for cypermethrin pesticide detection. The morphology surface of the fabricated electrode was characterized by atomic force microscopy. The electrochemical study was characterized by cyclic voltammetry and impedance spectroscopy using a fabricated electrode as a working electrode, platinum sheet as a counter electrode and silver/silver chloride as a reference electrode. The fabricated electrode has suitable detection for cypermethrin with good selectivity, high sensitivity at 0.279 μA ppm-1, low limit of detection at 0.34 ppm, high accuracy, is inexpensive and can be applied to the portable electrochemical sensor device for detection of cypermethrin in real samples.
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Effect of amino-, mercapto-silane coupling as a molecular bridge of polyvinyl chloride ion-selective membrane on silicon nitride for nitrate ISFET sensors
(2020-06-01)
Chaisriratanakul, Woraphan
;
Bunjongpru, Win
;
Pankiew, Apirak
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Srisuwan, Awirut
;
Jeamsaksiri, Wutthinan
This paper presents a modification of a Si<inf>3</inf>N<inf>4</inf> Polyvinyl chloride (PVC) membrane on a surface of an ion selective field effect transistor (ISFET) using silane with two different functional groups for comparison of nitrate sensing characteristics. Effects of amino (NH<inf>2</inf>) and thiol groups (SH) toward structures and characteristics of nitrate sensors were analyzed using the following techniques: ellipsometry, scanning electron microscope (SEM), infrared spectroscopy (FTIR), zeta potential and electrochemical impedance spectroscopy (EIS). After surface modification, the thickness of the silane layers for both cases were similar with uniform surface topology. Absolute zeta potentials of PVC ion-selective membrane (7.65 mV) and Si<inf>3</inf>N<inf>4</inf> surface modification with MPTMS (-51.46 mV) reflected the surface functional group and showed that membranes could be bonded to the PVC ion-selective membrane. Since APTMS produced higher EIS than MPTMS, the resulting nitrate sensors modified by MPTMS had higher sensitivity than the sensors with APTMS. Finally, the modified sensors had a useful life time of 3 months.
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Enhancement of Electrochemical Detection of Gluten with Surface Modification Based on Molecularly Imprinted Polymers Combined with Superparamagnetic Iron Oxide Nanoparticles
(2022-01-01)
Limthin, Dalawan
;
Leepheng, Piyawan
;
Klamchuen, Annop
;
Phromyothin, Darinee
Novel molecularly imprinted polymers (MIPs) represent a selectively recognized technique for electrochemical detection design. This rapid and simple method prepared via chemical synthesis consists of a monomer crosslinked with an initiator, whereas low sensitivity remains a drawback. Nanomaterials can improve charge transfer for MIP surface modification in order to overcome this problem. SPIONs have semiconductor and superparamagnetic properties that can enhance carrier mobility, causing high sensitivity of electrochemical detection. In this work, surface modification was achieved with a combination of MIP and SPIONs for gluten detection. The SPIONs were synthesized via the chemical co-precipitation method and mixed with MIPs by polymerizing gluten and methyl methacrylate (MMA), presented as a template and a monomer. Magnetic MIP (MMIP) was modified on a carbon-plate electrode. The morphology of modified electrode surfaces was determined by scanning electron microscopy–energy-dispersive X-ray spectrometry. The performance of the MMIP electrode was confirmed by cyclic voltammetry, amperometry, and electrochemical impedance spectroscopy. The MMIP electrode for gluten detection shows a dynamic linear range of 5–50 ppm, with a correlation coefficient of 0.994 and a low detection limit of 1.50 ppm, which is less than the U.S. Food and Drug Administration requirements (20 ppm); moreover, it exhibits excellent selectivity, sensitivity, stability, and reproducibility.
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Efficiency of SPIONs functionalized with polyethylene glycol bis(amine) for heavy metal removal
(2016-09-15)
Wanna, Yongyuth
;
Chindaduang, Anon
;
Tumcharern, Gamolwan
;
Phromyothin, Darinee
;
Porntheerapat, Supanit
Hybrid magnetic nanoparticles based on poly(methylmethacrylate) (PMMA) and super-paramagnetic iron oxide nanopaticles (SPIONs) with selective surface modification has been developed for heavy metal removal by applying external magnetic fields. The nanoparticles were prepared by the emulsion polymerization technique in an aqueous suspension of SPIONs. The hydrolysis of carboxyl functional group was then applied for grafting polyethylene glycol bis(amine)(PEG-bis(amine)) onto the PMMA-coated SPIONs. The morphology, the chemical structure and the magnetic properties of the grafted nanoparticles were investigated. The efficiency of the hybrid nanoparticles for heavy metal removal were conducted on Pb(II), Hg(II), Cu(II) and Co(II) in aqueous solutions.The metal concentration in the solutions after separation by the hybrid nanoparticles was determined by inductively coupled plasma optical emission spectrometer (ICP-OES). The results show the heavy metal uptake ratios of 0.08, 0.04, 0.03, and 0.01 mM per gramme of the grafted SPIONs for Pb(II), Hg(II), Cu(II), and Co(II), respectively. A competitive removal of Cu(II), Pb(II), Co(II) and Hg(II) ions in mixed metal salt solutions has also been studied.The heavy metal removal efficiency of the hybrid nanoparitcles was found to depend on the cation radius, in accordance with capture of metal ions by the amine group.
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Modification of polyvinyl chloride ion-selective membrane for nitrate ISFET sensors
(2020-05-15)
Chaisrirattanakua, Woraphan
;
Bunjongpru, Win
;
Pankiew, Apirak
;
Srisuwan, Awirut
;
Jeamsaksiri, Wutthinan
In this work, a Polyvinyl Chloride (PVC) ion-selective membrane was modified to detect nitrate based on Ion Selective Field Effect Transistor (ISFET) sensing technology in order to eliminate chloride interference. A modification was done with ethylenediamine solution to achieve animated PVC, which was then oxidized with sodium tungstate to form nitrone coated PVC membrane. The modified PVC was characterized using FTIR, 1H NMR, GPC, FE-SEM and EIS. The FTIR spectrum of animate PVC demonstrated -NH<inf>2</inf> bending at 1580 cm−1, NO<inf>2</inf> asymmetric stretching at 1650 cm−1 and N[sbnd]O out-of-plane deformation vibration at 837 cm−1. GPC analysis of the modified PVC showed that the PVC molecular weight was shifted to a high molecular weight. The PVC ion-selective membrane was immobilized on the ISFET to create nitrate sensors with the following characteristics. The Nitrate-Nitrogen detection limit is 1.20 ppm with linear range from 3−20 ppm at sensitivity of 56 ± 2 mV/dec. The sensor is useful for detecting small amount of nitrate in a mixed solution, which usually is the case in most situations. This sensor could be applied in many applications, such as agricultural industry, water reserve management and medical field as well.
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Selective electrochemical determination based on magnetic molecularly imprinted polymers for albumin detection
(2022-06-01)
Leepheng, Piyawan
;
Limthin, Dalawan
;
Onlaor, Korakot
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Tunhoo, Benchapol
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Thiwawong, Thutiyaporn
Egg allergy is one of the most common allergies in humans. Allergenic egg protein as ovalbumin is the most abundant protein found in egg white. A selective electrode in electrochemical analysis for albumin from egg white was developed based on magnetic molecularly imprinted polymers (albumin-MMIPs) modified on a screen-printed electrode. Surface modification was applied using methyl methacrylate polymer to create surface specificity for albumin protein. The modified surface was characterized by a field-emission scanning electron microscope (FE-SEM). The average pore size was obtained by Brunauer-Emmett-Teller (BET) analysis, and the potentiostat obtained all electrochemical analysis. The albumin-MMIP electrode was selectivity with albumin, comparison with gluten, glycine, casein, and glucose. The modified electrodes present selectivity of 1.13 × 104 μAg-1ml and a limit of detection of 0.18 mg ml-1. The electrode can be applied to albumin protein detection in solution form in food industries.
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Enhancing the sensitivity and selectivity of salbutamol detection using reduced graphene oxide combined with molecularly imprinted polymers (RGO/MIP)
(2022-06-01)
Limthin, Dalawan
;
Leepheng, Piyawan
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Onlaor, Korakot
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Tunhoo, Benchapol
;
Klamchuen, Annop
In this study, to enhance the selectivity and sensitivity of salbutamol detection performed by a carbon plate electrode, the electrode was modified using a novel molecularly imprinted polymer (MIP) combined with reduced graphene oxide (RGO). The RGO/MIP combination was prepared by the polymerization of methacrylic acid as a monomer using salbutamol as a template. The surface morphologies of the modified electrodes were studied using field-emission scanning electron microscopy (FE-SEM), and their performance was tested by an electrochemical technique that investigated both the cyclic voltammetry (CV) and amperometry (AMP) modes. The performance of the modified RGO/MIP electrode was compared with that of an MIP electrode, in which the RGO/MIP electrode was demonstrated to have 4.16 nA/ppm of sensitivity, more than the 0.91 nA/ppm of the MIP electrode. The limit of detection (LOD) of the RGO/MIP electrode, which was 0.83 ppm, was lower than that of the MIP electrode. Moreover, the RGO/MIP electrode’s dynamic range extended from 1 to 1000 ppm, and it exhibited consistency, repeatability, a fast response, and high selectivity for salbutamol detection.
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Key role of hydrazine to the interaction between oxaloacetic against phosphoenolpyruvic carboxykinase (PEPCK): ONIOM calculations
(2013-08-01)
Prajongtat, Pongthep
;
Phromyothin, Darinee Sae Tang
;
Hannongbua, Supa
The interactions between oxaloacetic (OAA) and phosphoenolpyruvic carboxykinase (PEPCK) binding pocket in the presence and absence of hydrazine were carried out using quantum chemical calculations, based on the two-layered ONIOM (ONIOM2) approach. The complexes were partially optimized by ONIOM2 (B3LYP/6-31G(d):PM6) method while the interaction energies between OAA and individual residues surrounding the pocket were performed at the MP2/6-31G(d,p) level of theory. The calculated interaction energies (INT) indicated that Arg87, Gly237, Ser286, and Arg405 are key residues for binding to OAA with the INT values of -1.93, -2.06, -2.47, and -3.16 kcal mol-1, respectively. The interactions are mainly due to the formation of hydrogen bonding interactions with OAA. Moreover, using ONIOM2 (B3LYP/6-31G(d):PM6) applied on the PEPCKHS complex, two proton transfers were observed; first, the proton was transferred from the carboxylic group of OAA to hydrazine while the second one was from Asp311 to Lys244. Such reactions cause the generation of binding strength of OAA to the pocket via electrostatic interaction. The orientations of Lys243, Lys244, His264, Asp311, Phe333, and Arg405 were greatly deviated after hydrazine incorporation. These indicate that hydrazine plays an important role in terms of not only changing the conformation of the binding pocket, but is also tightly bound to OAA resulting in its conformation change in the pocket. The understanding of such interaction can be useful for the design of hydrazine-based inhibitor for antichachexia agents. [Figure not available: see fulltext.] © 2013 Springer-Verlag Berlin Heidelberg.
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Functionalized magnetic nanoparticles as chemosensors based on fluorene derivative for Cd(II) ions detection
(2019-11-18)
Thanakit, P.
;
Limthin, D.
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Leepheng, P.
;
Suramitr, S.
;
Phromyothin, D.
Chemosensor of fluorene derivative (FL) contains different conjugated aromatic rings and binding sites that indicate the maximum fluorescence spectra at 505 nm in dimethylformamide solvation. The emission color is sensitive to changes in acidity and basicity solution which explain in twisted-intramolecular charge transfer and results in a sensitivity of metal ions. At neutral solution (pH 7), these molecules are sensitive to Cd(II) ions which illustrate red-shifted fluorescence spectra and the increase of Cd(II) ions concentration results in the increases of the fluorescence intensity. The limit of detection (LOD) of Cd(II) ions is 0.289 mg/L. The presence of other metal ions in Cd(II)-complexes shows the selectivity of Cd(II) ions and was not significantly sensitive to other metal ions. The carboxylic binding sites of FL chemosensor are important to interact with Cd(II) ions in dimethylformamide solvation and the cyano moiety can withdraw the charge transfer to binding site results in fluorescence intensity increasing. In addition, superparamagnetic iron oxide nanoparticles (SPIONs) were used to improve signal fluorescence intensity for Cd(II) ions detection which lead to the lower limit of detection. The surface of SPIONs was modified with PMMA that it exhibits the decreased agglomeration of SPIONs. Then, the suspension of fluorescent magnetic nanoparticles was showed the good solubility in dimethylformamid when FL was coated on the PMMA/SPIONs.
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An experimental and theoretical study of molecularly imprinted electrode based on methyl methacrylate polymer for pesticide detection
(2020-06-01)
Leepheng, Piyawan
;
Limthin, Dalawan
;
Homchan, Wisa
;
Suramitr, Songwut
;
Phromyothin, Darinee
A selective electrode based on molecularly imprinted polymer (MIP) was developed by the polymerization of methyl methacrylate polymer on a screen-printed electrode for pesticide detection. Cypermethrin is one of the pesticides in the pyrethroid group, which has high toxicity in an organism and humans and causes environmental pollution. Cypermethrin-MIP and non-imprinted polymer films on electrodes were characterized for their surface morphology. The electrochemical analysis of cypermethrin pesticide was measured by amperometry under the potential of -0.23 V versus Ag/AgCl. Decreasing the current was directly proportional to the concentration of cypermethrin in the range of 15.50 ppb-10.00 ppm, and the limit of detection value was calculated to be 15.00 ppb. The proposed modified electrode has high sensitivity of 0.094 μA ppm-1 and effective selective detection of cypermethrin in samples of real vegetable juice. The computational analyses were performed with the density functional theory at M06-2x/6-31 g(d,p), which predicted interaction and study mechanism between the MIP matrix with target pesticides.

Phromyothin, Darinee

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