Kayunkid, Navaphun

Preferred name

Kayunkid, Navaphun

Alternative Name

Kayunkid, N.

Kayunkid, Nawapun

Main Affiliation

Integrated Innovative Technology

navaphun.ka@kmitl.ac.th

Now showing 1 - 10 of 25

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Metal Oxide Nanostructures Enhanced Microfluidic Platform for Efficient and Sensitive Immunofluorescence Detection of Dengue Virus
(2023-11-01)
Pormrungruang, Pareesa
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Phanthanawiboon, Supranee
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Jessadaluk, Sukittaya
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Larpthavee, Preeda
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Thaosing, Jiraphon
Rapid and sensitive detection of Dengue virus remains a critical challenge in global public health. This study presents the development and evaluation of a Zinc Oxide nanorod (ZnO NR)-surface-integrated microfluidic platform for the early detection of Dengue virus. Utilizing a seed-assisted hydrothermal synthesis method, high-purity ZnO NRs were synthesized, characterized by their hexagonal wurtzite structure and a high surface-to-volume ratio, offering abundant binding sites for bioconjugation. Further, a comparative analysis demonstrated that the ZnO NR substrate outperformed traditional bare glass substrates in functionalization efficiency with 4G2 monoclonal antibody (mAb). Subsequent optimization of the functionalization process identified 4% (3-Glycidyloxypropyl)trimethoxysilane (GPTMS) as the most effective surface modifier. The integration of this substrate within a herringbone-structured microfluidic platform resulted in a robust device for immunofluorescence detection of DENV-3. The limit of detection (LOD) for DENV-3 was observed to be as low as 3.1 × 10−4 ng/mL, highlighting the remarkable sensitivity of the ZnO NR-integrated microfluidic device. This study emphasizes the potential of ZnO NRs and the developed microfluidic platform for the early detection of DENV-3, with possible expansion to other biological targets, hence paving the way for enhanced public health responses and improved disease management strategies.
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The enhancement of sensitivity and response times of PDMS-based capacitive force sensor by means of active layer modification
(2021-06-01)
Siangkhio, Yasumin
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Rangkasikorn, Adirek
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Tammarugwattana, Narin
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Kayunkid, Navaphun
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Jessadaluk, Sukittiya
In this work, sensitivity and response times of PDMS-based capacitive force sensors are enhanced via the modifications of the PDMS layer. Two modifying approaches are proposed; (i) change PDMS's (elastomer:curing agent) ratio and (ii) adding conductive polymer PEDOT:PSS into the PDMS layer. The change of PDMS (elastomer:curing agent) ratio from (10:1) to (30:1) increases the sensitivity from 0.4 0.08 to 0.72 0.23 kPa-1 (+80%) but it does not significantly affect the response/recovery times. In addition, by adding 1% wt. of PEDOT:PSS to PDMS (30:1), the further increment of sensitivity from 0.72 0.23 to 1.44 0.17 kPa-1 (+100%) and the shorter response time from 1.59 0.02 to 0.45 0.03 s (-72%) are observed. The mechanical and electrical studies reveal that the change of PDMS (elastomer:curing agent) ratio and the adding of PEDOT:PSS to PDMS layer result in the modification of PDMS's deformability and the increase of charge transportation, leading to the enhancement of sensing characteristics of the sensors.
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The decoration of ZnO nanoparticles by gamma aminobutyric acid, curcumin derivative and silver nanoparticles: Synthesis, characterization and antibacterial evaluation
(2021-02-01)
Talodthaisong, Chanon
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Plaeyao, Kittiya
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Mongseetong, Chatariga
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Boonta, Wissuta
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Srichaiyapol, Oranee
Zinc oxide nanoparticles (ZnO NPs) are applied in various applications in catalysis, bio-sensing, imaging, and as antibacterial agents. Here we to prepare ZnO nanomaterials decorated by γ-amino butyric acid (GABA), curcumin derivatives (CurBF2) and silver nanoparticles (CurBF2-AgNPs). The structures of all ZnO nanostructures were characterized using Fourier transform in-frared (FT-IR) spectroscopy, X-ray diffraction (XRD), UV–VIS spectrophotometry, fluorescence spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HR-TEM). Further, their antibacterial activities against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria were investigated through analysis of minimum inhibitory concentration (MIC) method. Among the prepared nanostructures, the ZnO NPs-GABA/CurBF2-AgNPs showed excellent antibacterial activity against both Gram-positive and-negative bacteria. ZnO NPs fabricated here may have potential use in future anti-bacterial compositions and coatings technologies.
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Influence of Dragon Fruit Peels on the Synthesis of Antibacterial Nano Zinc Oxide (Nano-ZnO) via Green Synthesis Method
(2026-05-20)
Sakulpeeb, Natchayaporn
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Koetniyom, Wantana
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Chutipaijit, Sutee
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Rahong, Sakon
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Kayunkid, Navaphun
This research focused on adding value to dragon fruit peel waste by utilizing it in the synthesis of antibacterial nano zinc oxide (Nano-ZnO) through a green synthesis process. In this study, all the dragon fruit peels were extracted using the solvent extraction technique with three different solvents (deionized water, ethanol, and methanol) for 1, 2, 3, 4, and 5 h, respectively. The amount of flavonoids from the extract was determined using UV-Vis spectrophotometer to obtain the optimum extraction time, which was 4 h for DI water as the solvent. Moreover, antibacterial Nano-ZnO was synthesized successfully by a green synthesis process using zinc nitrate Zn(NO3)2 and the extracts. The molecular vibrations as well as the crystal structure and morphology were investigated by Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM), respectively. Additionally, the antibacterial efficacy of the nano-zinc oxide samples was evaluated using disc diffusion method. Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) were the test agents. The research shows that the X-ray diffraction patterns of all synthesized ZnO nanoparticles (NPs) exhibited a wurtzite (hexagonal) crystal structure. FT-IR spectroscopy confirmed the presence of Zn-O stretching vibrations at approximately 500 cm⁻¹. Furthermore, the FE-SEM reveals that ZnO-yellow particles displayed spherical morphologies with an average particle size of 145 nm. At the same time, ZnO-White and ZnO-Red nanoparticles exhibited a combination of rod-like and elliptical morphologies, with average particle sizes of 168 nm and 321 nm, respectively. In addition, the antibacterial activity demonstrates effective inhibition against S. aureus and E. coli in all three ZnO nanoparticle conditions.
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A Shear-Thinning, Self-Healing, Dual-Cross Linked Hydrogel Based on Gelatin/Vanillin/Fe3+/AGP-AgNPs: Synthesis, Antibacterial, and Wound-Healing Assessment
(2023-12-01)
Talodthaisong, Chanon
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Patramanon, Rina
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Thammawithan, Saengrawee
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Lapmanee, Sarawut
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Maikaeo, Lamai
A shear-thinning and self-healing hydrogel based on a gelatin biopolymer is synthesized using vanillin and Fe3+ as dual crosslinking agents. Rheological studies indicate the formation of a strong gel found to be injectable and exhibit rapid self-healing (within 10 min). The hydrogels also exhibited a high degree of swelling, suggesting potential as wound dressings since the absorption of large amounts of wound exudate, and optimum moisture levels, lead to accelerated wound healing. Andrographolide, an anti-inflammatory natural product is used to fabricate silver nanoparticles, which are characterized and composited with the fabricated hydrogels to imbue them with anti-microbial activity. The nanoparticle/hydrogel composites exhibit activity against Escherichia coli, Staphylococcus aureus, and Burkholderia pseudomallei, the pathogen that causes melioidosis, a serious but neglected disease affecting southeast Asia and northern Australia. Finally, the nanoparticle/hydrogel composites are shown to enhance wound closure in animal models compared to the hydrogel alone, confirming that these hydrogel composites hold great potential in the biomedical field.
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PMMA/High-k Self-assembled TiO2 /PMMA Multi-layer Gate Dielectric for P3HT Organic Field Effect Transistors
(2022-01-01)
Inpor, Kroekchai
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Houngkamhang, Nongluck
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Thanachayanont, Chanchana
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Prichanont, Seeroong
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Kayunkid, Navaphun
In this work, a multi-layer structure of poly (methyl methacrylate)/ titanium dioxide/poly (methyl methacrylate) (PMMA/TiO₂ /PMMA; PTP) was proposed as a top-gate insulator for P3HT-based organic field-effect transistors (OFETs). Adding a TiO₂ interlayer as a high dielectric constant (high-k) material into PMMA film enables the modification of the dielectric constant of the multi-layers PTP film. The content of TiO₂ in the PTP film, which can be varied by changing the number of soaking cycles in TiO₂ solution, plays a crucial rule in modifying the dielectric constant of the PTP film. The higher the TiO₂ content used in the PTP film, the higher the dielectric constant of PTP film can be obtained. However, using high TiO₂ content led to a reduction in the dielectric constant of the PTP film due to leakage current induced by the agglomeration of TiO₂. The utilization of the top-gate insulator containing TiO₂ significantly enhanced several P3HT-OFETs characteristics, e.g., an increase in the I<inf>on</inf>/I<inf>off</inf> ratio, and a decrease in the threshold voltage. However, the use of the PTP top-gate insulator with a high content of TiO₂ resulted in regressions in the OFETs characteristics, such as a decrease in carrier mobility and reduction in the I<inf>on</inf>/I<inf>off</inf> ratio. OFETs operating at the optimum conditions of the PTP gate-insulator, with PTP thickness of 225 nm and RMS roughness of 20.0 nm, provided a dielectric constant of 7.13, a threshold voltage of-8.49 V, a saturation mobility of 2.2× 10-4 cm²V-1s-1, I<inf>on</inf>/I<inf>off</inf> ratio of 37.9, and a subthreshold slope of 0.39 V/decade.
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Simultaneous Improvement in Photovoltaic Performance and Air Stability of Perovskite Solar Cells by Controlling Molecular Orientation of Spiro-OMeTAD
(2024-07-22)
Sukgorn, Nuttaya
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Kaewprajak, Anusit
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Rodbuntum, Sasiphapa
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Kayunkid, Navaphun
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Rujisamphan, Nopporn
2,2′,7,7′-Tetrakis (N,N-di-p-methoxyphenyl-amine)9,9′-spirobifluorene (Spiro-OMeTAD) is a prototypical hole transport layer (HTL) for high-performance perovskite solar cells (PSCs). Since the electric conductivity of a neat Spiro-OMeTAD film is low, the HTL is generally doped with additives to increase charge density and mobility. However, the doped Spiro-OMeTAD film suffers from moisture absorption, which deteriorates the long-term stability of PSCs. This work reports that the molecular orientation of Spiro-OMeTAD molecules in the doped HTL is vital to solving this issue. Templating the molecular arrangement of Spiro-OMeTAD by a solidifying solvent, 1,3,5-trichlorobenzene (135-TCB), forms an anisotropic film of the doped Spiro-OMeTAD and induces a face-on orientation along the surface normal. Modifying the molecular orientation enhances hole mobility in the HTL and extraction of holes at the perovskite/HTL interface. As a result, the maximum power conversion efficiency (PCE) of the PSCs increases from 17.63 to 19.92%. Besides, the air stability of the PSCs with the face-on Spiro-OMeTAD, after storage for 1000 h, is superior to that of the devices without templating the molecular arrangement of Spiro-OMeTAD by 135-TCB. Control of the molecular orientation of Spiro-OMeTAD is critical for improving PCE and air stability.
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An unconventional blade coating for low-cost fabrication of PCDTBT: PC70BM polymer and CH3NH3PbIxCl3-x perovskite solar cells
(2021-04-01)
Kaewprajak, Anusit
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Kumnorkaew, Pisist
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Lohawet, Khathawut
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Duong, Binh
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Chonsut, Teantong
A low-cost and unconventional blade coating technique, called convective deposition, has been introduced for PCDTBT:PC<inf>70</inf>BM polymer and CH<inf>3</inf>NH<inf>3</inf>PbI<inf>x</inf>Cl<inf>3-x</inf> perovskite solar cell fabrication. With the new technique, only 10–20 microliter droplets per one square inch substrate were used to deposit hole transporting material, as well as photoactive and electron transporting materials, sequentially to create a p-i-n structure solar cell. Thin film deposition and solar cell fabrication from the standard spin coating and the convective deposition were compared. Smaller and better distribution of PC<inf>70</inf>BM domain in the PCDTBT:PC<inf>70</inf>BM film was observed in the film prepared by the convective deposition. Unlike the conventional doctor-blade coating or the spin coating, the film thickness can simply be adjusted by the convective deposition speed. The highest averaged power conversion efficiency (PCE) of 6.34% was obtained from the polymer solar cell prepared by the convective deposition at the coating speed of 750 μm/s compared to 5.60% PCE from the spin coating at the speed of 2500 rpm. For perovskite solar cell, a heating stage was used during the convective deposition of perovskite ink, 10.61% PCE was achieved with the stage temperature of 70 °C and the 2500 μm/s deposition speed. Layer-by-layer deposition with the convective deposition used in this study offers benefits over the standard spin coating by reducing amount of material consumption in the fabrication process and being suitable for low-cost fabrication of other solution-based optoelectronic devices.
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Enhancing Perovskite Thin Films with Butylammonium Iodide-Lead-Tetrahydrofuran: Surface Healing and 2D Formation in Annealing-Free Single-Crystal Films for Solar Cell Applications
(2024-04-01)
Azad, Farhad
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Supasai, Thidarat
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Yaro, Annafi Ado
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Soe, Kay Thi
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Thongprong, Non
We demonstrate a functional method to achieve surface passivation and construct a two-dimensional (2D) layer on a three-dimensional (3D) perovskite, eliminating the need for subsequent annealing steps. A key process is the integration of a single methylammonium lead iodide (MAPbI<inf>3</inf>) crystal with butylammonium iodide (BAI) in tetrahydrofuran. Density functional theory calculations reveal that the synergy between BA+ cations and Pb-I octahedral structures enables the formation of a distinct 2D layered framework. MA+ and BA+ exhibit adsorption energies of −5.519 and −5.925 eV, respectively, at MA vacancies on the perovskite surface. This finding indicates that BAI passivation induces surface-healing effects, increasing surface and device stability. The I- components of BAI also replace imperfections at the perovskite interface, affording considerably reduced deep-level anomalies and mitigating nonradiative recombination. This theoretical perspective is supported experimentally via X-ray photoelectron spectroscopy and glow discharge optical emission spectroscopy. BAI passivation and 2D-BA<inf>2</inf>PbI<inf>4</inf> capping lowers work functions for 3D perovskite surfaces, registering at approximately 0.158 and 0.173 eV, respectively, which are lower than those of the control 3D film. Within the 2D/3D perovskite configuration, 2D-BA<inf>2</inf>PbI<inf>4</inf> capping considerably increases the open-circuit voltage in solar cells. In comparison, devices with BAI-enhanced interfaces show improved durability with promise for solar cell applications.
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Selective formations of antimony-dopant for highly sensitive nitrogen dioxide responsive behavior of tin oxide-based chemiresistive sensor
(2025-02-15)
Rattanawarinchai, Prapakorn
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Khemasiri, Narathon
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Rahong, Sakon
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Rangkasikorn, Adirek
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Kayunkid, Navaphun
Here, selective formation of antimony (Sb) dopant species responsible for highly sensitive gas sensors based on tin oxide (SnO<inf>2</inf>) film grown via pulsed laser deposition is presented. By elevating a forming energy through controlling substrate temperature, not only crystallinity of Sb-SnO<inf>2</inf> (ATO) is notably enhanced but the Sb5 + also predominantly replace at Sn4+ site rather than Sb3+ counterpart. Such Sb-species selection plays a crucial role on the density of oxygen vacancy and free electron enabling to rationally design conductive behaviour of ATO film from insulative to degenerated semiconductor. As a practical example, detection of nitrogen dioxide (NO<inf>2</inf>) gas is selected as an application model. We found a narrow window for high NO<inf>2</inf> sensing performance of ATO film which strongly corresponds with the amount of carrier density. At certain window, ATO film exhibits high NO<inf>2</inf> response of 24.65 (10 ppm) and low limit of detection of 0.5 ppm, which is 5-fold higher and 10-fold lower than that of undoped-SnO<inf>2</inf>, respectively. Our finding demonstrates a facile approach to design over the chemical state, defect, and conductivity of the active sensing layer, allowing us to achieve an excellent sensing performance of functional materials conjugated to a nano-electronic platform.

Kayunkid, Navaphun

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