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 16

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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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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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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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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.
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Biodegradable antibacterial food packaging based on carboxymethyl cellulose from sugarcane bagasse/cassava starch/chitosan/gingerol extract stabilized silver nanoparticles (Gin-AgNPs) and vanillin as cross-linking agent
(2025-02-28)
Plaeyao, Kittiya
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Talodthaisong, Chanon
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Yingyuen, Worapol
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Kaewbundit, Ramet
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Tun, Wonn Shweyi Thet
The increasing issue of plastic waste necessitates improved solutions, and biodegradable food packaging is a promising alternative to traditional plastic. In this study, we prepared packaging films using cassava starch (CV), chitosan (CT) and carboxymethyl cellulose (CMC), with glycerol as a plasticizer. However, these films require modifications to enhance their mechanical properties. Therefore, we modified the films by adding vanillin as the crosslinking agent and gingerol extract stabilized silver nanoparticles. The films were fabricated using the film-casting method and characterized by FTIR, XRD, SEM, TGA, mechanical property test, biodegradability test, anti-bacterial test and food packaging evaluation test. Among these films, CT/CV/V/CMC/Gin-AgNPs1 exhibited superior mechanical properties and demonstrated excellent anti-bacterial property both for gram-positive (S. aureus) and gram-negative (E. coli) bacteria and biodegradability, losing over <inf>50%</inf> of its weight after 21 days of burial in soil and effectively preserved grapes at 4 °C for 21 days.
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Influence of Antimony Species on Electrical Properties of Sb-Doped Zinc Oxide Thin Films Prepared by Pulsed Laser Deposition
(2023-06-01)
Jessadaluk, Sukittaya
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Khemasiri, Narathon
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Kayunkid, Navaphun
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Rangkasikorn, Adirek
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Wirunchit, Supamas
This study systematically investigates the influence of antimony (Sb) species on the electrical properties of Sb-doped zinc oxide (SZO) thin films prepared by pulsed laser deposition in an oxygen-rich environment. The Sb species-related defects were controlled through a qualitative change in energy per atom by increasing the Sb content in the Sb<inf>2</inf>O<inf>3</inf>:ZnO-ablating target. By increasing the content of Sb<inf>2</inf>O<inf>3</inf> (wt.%) in the target, Sb3+ became the dominant Sb ablation species in the plasma plume. Consequently, n-type conductivity was converted to p-type conductivity in the SZO thin films prepared using the ablating target containing 2 wt.% Sb<inf>2</inf>O<inf>3</inf>. The substituted Sb species in the Zn site (Sb<inf>Zn</inf>3+ and Sb<inf>Zn</inf>+) were responsible for forming n-type conductivity at low-level Sb doping. On the other hand, the Sb–Zn complex defects (Sb<inf>Zn</inf>–2V<inf>Zn</inf>) contributed to the formation of p-type conductivity at high-level doping. The increase in Sb<inf>2</inf>O<inf>3</inf> content in the ablating target, leading to a qualitative change in energy per Sb ion, offers a new pathway to achieve high-performing optoelectronics using ZnO-based p–n junctions.
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Tailoring ZnO Nanostructures through Precursor Concentration and Hydrothermal Duration: A Pathway to Efficient Solar Water Splitting
(2026-11-10)
Borklom, Phanlapa
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Khemasiri, Narathon
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Jessadaluk, Sukittaya
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Rattanawarinchai, Prapakorn
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Kayunkid, Navaphun
This work investigated the formation of ZnO nanostructures on ITO substrates prepared by self-seeding hydrothermal synthesis for photoelectrochemical ( PEC) water splitting applications. The hydrothermal parameters, precursor concentration and hydrothermal time, were varied to explore their influences on ZnO crystallinity, morphology, and PEC performance. The combinations of X-ray diffraction and field emission scanning electron microscopy revealed highly oriented ZnO nanostructures with diverse morphologies, including small granules, nanorods, dense films, and hexagonal platelets. Topographic profiling of the morphological parameters revealed complex relationships between synthesis conditions and nanostructure characteristics, highlighting the importance of considering aggregation phenomena in substrate-based growth. This aggregation led to deviations from conventional crystal growth theory predictions, particularly for grain density and diameter evolution. PEC performance evaluation identified ZnO nanorods as the optimal morphology, exhibiting a photocurrent density of 0.182 mA/cm² at 0 V vs. Ag/AgCl. Further enhancement was achieved by decorating ZnO nanorods with CdS nanoparticles, resulting in a six-fold increase in photocurrent density (1.2 mA/cm²). This improvement is attributed to expanded light absorption and improved charge separation at the CdS/ ZnO interface. Our findings demonstrate the potential of rationally designed ZnO-based nanostructures in the advancement of solar-driven water splitting technologies and provide valuable insights for optimizing PEC systems through precise control of hydrothermal synthesis parameters, consideration of substrate-induced aggregation, and strategies for photoelectrochemical (PEC) water splitting applications.
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Growth window and metal-insulator transition behavior of VO2 thin films deposited by pulsed laser deposition for thermal switch applications
(2026-05-01)
Jessadaluk, Sukittaya
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Rahong, Sakon
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Kayunkid, Navaphun
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Khemasiri, Narathon
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Rangkasikorn, Adirek
Vanadium dioxide (VO<inf>2</inf>) is a strongly correlated transition metal oxide that exhibits a sharp and reversible metal-insulator transition (MIT) near room temperature, making it a promising material for thermal switching and adaptive electronic applications. In this study, VO<inf>2</inf> thin films were deposited on single-crystalline Si, thermally grown SiO<inf>2</inf>, and fused quartz substrates by pulsed laser deposition, and the influence of substrate temperature and oxygen partial pressure on phase formation, structural properties, and MIT behavior was systematically investigated. By optimizing deposition conditions within a narrow oxygen pressure window, phase-pure monoclinic VO<inf>2</inf>(M) thin films with high crystalline quality were achieved while suppressing the formation of over-oxidized vanadium oxide phases. Structural and chemical analyses using X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy confirmed the stabilization of the V4+ oxidation state and uniform film stoichiometry. Temperature-dependent electrical measurements revealed a pronounced and reproducible MIT characterized by an abrupt change in resistance and a clear thermal hysteresis. In-situ temperature-dependent X-ray diffraction further demonstrated a direct correlation between the monoclinic-rutile structural transformation and the electronic transition. Importantly, the MIT behavior was consistently observed across all investigated substrates, indicating robust film growth and substrate tolerance. These results provide insight into the structure-property relationships governing VO<inf>2</inf> thin films and highlight their potential for integration into thermal switch and thermally adaptive device architectures.

Kayunkid, Navaphun

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