Biosensors are devices that can measure and quantify biomarkers specialized for infectious diseases. Nanoparticles are extensively utilized in biosensors due to their ability to achieve low detection limits. However, biosensor performance can be significantly impacted by challenges such as slow electron transfer kinetics and limited surface area for biomolecule immobilization. Gold nanoparticles (AuNPs) are a type of plasmonic nanoparticle with exceptional optical and physical properties, making them promising for biomedical and analytical applications. This review summarizes common AuNP synthesis methods, their integration into biosensors, and their impact on the biosensors' performance. A literature survey covering the period from 2020 to 2024 was conducted using the Scopus database to examine the synthesis and application of AuNPs in biosensors. A systematic review of 20 studies was performed following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The review identified nine articles related to the conjugation of AuNPs with bioreceptors. Additionally, studies focusing on AuNPs synthesis methods and electrode modifications were identified, with two papers that addressed both synthesis and bioconjugation. The findings suggest a need for future research to explore alternatives, such as biological approaches to AuNP synthesis, and to further investigate modifications of various electrode surfaces with AuNPs.
The medium utilized in spectral splitting photovoltaic/thermal (PV/T) systems holds immense significance. Previously employed nanofluids, such as polypyrrole, Ag, ZnO, and MgO, exhibited insufficient absorption in the infrared range, hindering the photothermal units from achieving higher temperatures. Copper sulfide (CuS) emerges as a promising alternative nanofluid in PV/T systems due to its superior thermal conductivity and adjustable spectral radiation properties. To assess its suitability, four samples of CuS nanofluid are synthesized under four different oil bathing temperatures, which are 25 degrees C, 40 degrees C, 60 degrees C, and 80 degrees C, respectively. What is more, an in-depth examination of CuS nanofluid's optical characteristics and performance is conducted. The U-4100 Spectrophotometer was employed to measure its transmittance, while the Nicolet iS50 was employed to measure its reflectivity. The findings revealed that a 10 mm layer of CuS nanofluid synthesized under 80 degrees C oil bathing temperature possesses distinct selective absorption properties compared to the other three samples of CuS nanofluids. For this CuS nanofluid with the concentration of 100 ug/ml, the transmittance at the wavelength of 600 nm can hit 65 %, while the transmittance in the near-infrared wavelength band is lower than 16 %. These unique optical attributes underscore the potential for CuS nanofluid to be widely adopted in spectral splitting PV/T systems.
The increasing use of Carbon Fibre Reinforced Polymers (CFRPs) necessitates sustainable end-of-life solutions due to their environmental persistence and the high energy cost of virgin carbon fibre production. This work examines recent advancements in recycling technologies for CFRPs, including thermal, chemical, mechanical, and hybrid processes, and their impact on the mechanical and electrical properties of recycled carbon fibre composite. The review analyses how different recycling methods influence the overall composite performance. While mechanical properties like strength and stiffness are often prioritised, this review also addresses the less-studied area of dielectric properties, including electromagnetic interference shielding and electrical conductivity. The goal is to provide a comprehensive overview of the current state of recycled Carbon Fibre Reinforced Polymers (rCFRPs) technology, highlighting both opportunities and challenges for reuse and remanufacturing. The review concludes by identifying critical research gaps and future directions to fully realize the potential of rCFRPs as a sustainable alternative to virgin CFRPs in a wider range of structural and functional applications.
In recent years, the Floating Film Transfer Method (FTM) has gained attention as an innovative approach for fabricating organic thin-film transistors (OTFTs) using organic conjugated polymers. This innovative solution-processing technology provides advantages for the orientation of macroscopic conjugated polymers along with being straightforward processes with encouraging outcomes. Here, we review the recent research on this technology, covering the process mechanism and key variables that affect the mobility of organic thin-film transistors fabricated using this novel method. This review also addresses the ability of FTM to produce uniform thin films of semiconducting polymers on hydrophilic substrates. The review concludes by discussing the limitations and challenges of the FTM.
Bamboo nanocellulose (BNC), a biopolymer derived from renewable biomass, is recognized for its impressive mechanical strength, thermal stability, and biodegradability, making it an excellent choice for high-performance composite materials. Bamboo nanocellulose is transformed into lightweight, porous aerogels by undergoing alkali processing, delignification, and lyophilization, alongside other chemical and mechanical methods. These aerogels are a long-term and versatile framework for incorporating graphene oxide (GO), a material noted for its tunable electrical conductivity and outstanding electromagnetic absorption capabilities. Graphene oxide (GO) improves the aerogel’s electrical conductivity and electromagnetic wave absorption. With its tunable reduction state and outstanding conductive capabilities, GO integrates synergistically with bamboo nanocellulose via hydrothermal synthesis and in situ polymerization, resulting in a hierarchical structure that enhances EMI shielding effectiveness. The resulting BNC-GO aerogels have high electrical conductivity, thermal stability, and absorption-dominated electromagnetic shielding. Recent research has highlighted the efficiency of BNC-GO aerogels, with several measuring methodologies and electromagnetic wave absorption testing showing its strong shielding effectiveness over a wide frequency range. These findings emphasize the potential of bamboo nanocellulose as a sustainable matrix for graphene oxide-based composites, paving the way for eco-friendly, next-generation EMI shielding materials.
The field-effect transistor (FET) is a vital component in various electronic devices, including integrated circuits (ICS), switching modules, and microprocessors. The current technological breakthroughs have enabled the development of N5 (5 nm node) technology for fabricating transistors. Before the production of transistors, it was crucial to engage in modelling and simulation to reduce costs and save time. Hence, developing a methodology for predictingtransistor characteristics is essential for minimizing expenses and time in advancing transistor technology. Machine learning (ML) enables data-driven modeling of complex nonlinear systems to gain knowledge and enhance their performance without explicit programming. ML trains machines to optimize the processing and understanding of data. Researchers have conducted several studies to enable ML to acquire knowledge without explicit autonomous programming. However, the previous ML model achieved a coefficient of determination (R2) of only 0.98, or 98%. Here, we report on the use of Technology Computer-Aided Design (TCAD) to generate a dataset that achieves a high predictive performance. The Nanosheet Field-Effect Transistor (NSFET) can be modified by adjusting five essential factors: Gate Length (Lg), Sheet Width (Fw), Sheet Height (Fh), Spacer Length (Lsp), and equivalent oxide thickness (eot). An Artificial Neural Network (ANN) is used to forecast various features of NSFET, including Threshold Voltage (VT), Off-State Current (ioff), Saturation Current (isat), and Subthreshold Swing (sslop). The results indicate that the ANN model accurately predicts NSFET properties, yielding an R2 value of 0.9915 indicating strong correlation within the simulated dataset.
Freshwater ecosystems are increasingly threatened by microplastic (MP) pollution, which can bioaccumulate in aquatic organisms and pose ecological and human health risks. However, information on MP contamination in freshwater lakes of inland northwest China remains scarce, particularly in locally consumed fish species. This study examined the occurrence, characteristics, and ecological risks of microplastics (MPs) in goldfish (Carassius auratus) from Yuehai Lake, Ningxia, China. Fifty goldfish were collected, and their gills, intestines, and liver were dissected and digested with nitric acid. MPs were extracted, purified, and identified using Laser Direct Infrared Imaging (LDIR) spectroscopy. MPs were detected in all tissues, with an average abundance of 43.2 +/- 30.2 particles per individual. The gills exhibited the highest MP abundance, averaging 8.56 +/- 3.78 particles per fish, followed by the intestines (2.64 +/- 1.02 particles) and liver (1.76 +/- 0.48 particles). Across all tissues, 22 MP polymer types were identified, with nine polymers- such as polyethylene (PE), polyethylene terephthalate (PET), and polyvinyl chloride (PVC)-present in all organs. MPs predominantly ranged from 20 to 100 mu m, accounting for over 89% of MPs in all tissues. Fibers were the most prevalent morphology, comprising 61.69% in gills, 41.67% in intestines, and 68.29% in liver. Contamination factor (CF) values indicated moderate MP contamination in intestines (2.43) and liver (1.98), and considerable contamination in gills (4.72). Pollution load index (PLI) values exceeding 1 confirmed a general MP pollution burden in goldfish from Yuehai Lake. These findings provide critical baseline data for understanding MP contamination in inland freshwater environments and highlight the urgent need for targeted mitigation strategies.
Power MOSFET remains a key device platform in the semiconductor market demand, and this has drawn attention to SilTerra in the long-term supply chain, which provides additional manufacturing loading. In this work, the evaluation of the advanced cell pitch of a vertical trench MOSFET or U-MOSFET was selected due to its process compatibility in a CMOS fabrication environment. A major challenge was identified during the product ramping stage, exhibiting inconsistency for gate-to-source leakage (IcSS) on the wafer edge across different production lots, along with trench Final Inspection Critical Dimension (FICD) and threshold voltage (VTH) variation. Failure analysis revealed that affected IcSS failure wafers have shown a wider trench critical dimension (CD) and misalignment between the contact and trench on the wafer edge. Inline containment activities were implemented on precise process control for trench final inspection critical dimension (FICD) and tighter alignment measurement in order to achieve stable IcSS; however, this stringent inline process control has increased the rework rate. With the systematic trench mask development inspection critical dimension (DICD) split, it is confirmed that wider trench spacing or CD increases IcSS failure at the wafer edge and overall VTH variation; the optimal trench FICD control target is identified at 200 nm +/- 12 nm for stable IcSS performance, and it is observed that CD bias between DICD and FICD is not at zero. To address the alignment mark issues, the layout structure was evaluated using technology computer-aided design (TCAD) simulation and tape-out for the experiment. The result of the new alignment has demonstrated a better process margin with the lowest IcSS failure.
This study investigates the influence of infill patterns and densities on the tensile properties of Fused Deposition Modeling (FDM) 3D-printed Polylactic Acid (PLA) parts, aimingto optimize material efficiency while maintaining structural integrity. Eight infill patterns- Cross 3D, Subdivision Cubic, Octets, Quarter Cubic, Concentric, Grid, Gyroid, and Zigzag-were tested at 45%, 55%, and 65% infill densities, with a solid specimen (100% infill) serving as a benchmark. Tensile testing revealed that the Quarter Cubic pattern at 65% infill density closely matched the mechanical strength and stiffness of the solid specimen while significantly reducing material usage. Statistical analysis using the Taguchi method and ANOVA identified infill percentage as the most influential factor (p = 0.003), while regression modeling (R-2 = 91.88%) demonstrated robust predictive capability. This study contributes novel insights into the interplay between infill design and mechanical performance, guiding sustainable production of high-strength, lightweight PLA components for applications in aerospace, automotive, and consumer products.
Clitoria ternatea (CT), locally known as bunga telang, is traditionally used as a natural food colourant in Malaysia. However, its colour stability is limited due to its high sensitivity to heat. This study investigated the microencapsulation of CT-derived natural colourants gum, and chitosan. The CT flowers were extracted with an alkaline solution (pH 10.5), and encapsulation was performed using in situ polymerisation to facilitate microcapsule formation. The structural, morphological, and size characteristics of the microcapsules were analysed using field emission scanning electron microscopy (FESEM). The results revealed that capsule size varied depending on the polymer used. Among the tested polymers, PMMA microcapsules (1.13 +/- 0.12 & micro;m) demonstrated superior uniformity, sphericity, and smoother surfaces with fewer cracks compared to other polymers. Microencapsulation efficiency was further evaluated through ultraviolet-visible spectrophotometry, where PMMA microcapsules exhibited the highest absorbance profile, indicating their potential as an efficient polymer for encapsulating CT extracts. Thus, the microencapsulation of CT extracts, particularly with PMMA, is expected to enhance stability and broaden the application of this natural colourant in food, textile, and pharmaceutical industries.
With the rise in self-powered gadgets, triboelectric nanogenerators (TENGs) have emerged as a competent option for effective energy harvesting from mechanical motion. This research centers on the phenomenon of triboelectric charge generation at the interface of polyvinylidene fluoride (PVDF) and polyethylene terephthalate (PET) with respect to energy band theory. The study aims to improve the energy harvesting efficiency of TENGs through simulations and experimental work. Contact-separation TENG devices were constructed, and their performance was optimized using COMSOL software by varying parameters such as dielectric layer thickness, surface charge density, and distance. This work shows that TENG devices experience non-linear responses, which many traditional simulations fail to incorporate. Simulations alongside experimental results have shown that TENGs respond to applied force with voltage in a non-linear trend. Based on simulation results, the device has potential for substantial voltage generation; however, power density would benefit from improved geometric configuration and contact methods. This experimental validation supports simulation findings and highlights the PVDF/PET TENG's excellent energy-harvesting capability, even at the lower force levels. A major highlight of this study is that increasing dielectric spacing enhances output voltage and power density in dielectric-dielectric triboelectric nanogenerators. The application of this principle is thought to decrease the reliance on batteries, thereby addressing challenges related to recycling and disposal. This method could enable the advancement of more efficient and eco-friendly energy production and sensor technologies, suitable for applications in wearable electronics, healthcare, and industrial sectors.
The increase in cigarette confiscation by the Royal Malaysian Customs Department led to cigarette burning, contributing to raw materials wastage. Cellulose-rich cigarette filters (CF) can yield nanocrystalline cellulose (NCC) with potential applications in advanced materials. The NCC can be obtained by using sulfuric acid in the acid hydrolysis process. While sulfuric acid hydrolysis is a widely used method for extracting NCC, there is a lack of optimization of its parameters tailored to the cigarette filter as the raw material. This gap hinders the ability to consistently produce high-yield NCC, especially from non-traditional cellulose sources like cigarette butts. This study focuses on optimizing the extraction of NCC via sulfuric acid hydrolysis, utilizing a Box-Behnken experimental design to determine the optimized process parameters. The effects of acid concentration (33-35%), reaction temperature (45-75 degrees C), and hydrolysis time (40-90 min) on NCC yield percentage were evaluated. The FTIR confirmed the removal of non-cellulosic components from the CF without affecting the functional groups of cellulose, confirming that its structural integrity remains unaltered. Findings from this study recorded the highest yield by using sulfuric acid hydrolysis, which can reach up to 89.95% from the cigarette filters used. The findings provide a sustainable approach to turning zero-waste cigarettes' raw materials into sustainable advanced materials.
The presence of microplastic contaminants in bottled drinking water has raised growing concern due to their harmful effects on both human health and the environment. In this study, we investigate the occurrence of microplastics in 17 commercially available bottled water brands in Kota Kinabalu, Sabah, Malaysia. This study also quantifies the level of microplastics based on their sizes, shapes, colors, and polymer types. The associated risk through ingestion level of microplastics in drinking water was evaluated. The quantification analyses showed that the average abundance of MPs varied from 2 +/- 1 particles/L to 42 +/- 1.52 particles/L with the highest number of MPs found in brand D. The results showed that MPs were detected in four distinct forms (line, fragments, fibers, and pellet). MPs particle sizes ranged from 100 um - 5000 um with 38% of particles dominant in sizes 500 um to 1000 um. Microplastics were documented in five distinct colors, with black representing 48% of the total count. Infrared spectral analysis (FTIR) confirmed that the occurrence of high polypropylene (PP) polymers in bottled water primarily originate from the packaging materials and bottle caps. The estimated daily intake of microplastics (EDI) by children and adults was determined to be 0.53 and 0.19 particles/kg/day. These findings offer crucial data for a more in-depth assessment of the potential health risks linked to human exposure to microplastics.
The influence of 3 mol% cerium (Ce) in addition to the barium titanate (BaTiO3) on the structural, dielectric, and electrical behavior of BaTiO3 ceramics was examined using samples prepared through the conventional solid-state route. An X-ray diffraction was used to confirm the formation of a pure tetragonal perovskite phase, while a slight reduction in the tolerance factor suggested minor lattice distortion arising from Ce incorporation. From the dielectric measurements, the Curie temperature was shifted to around 60 degrees C, with a high permittivity value of approximately 7267 at 1 kHz, indicating that Ce doping effectively modifies the ferroelectric ordering within the lattice. The Arrhenius plot with an activation energy of 0.49 eV and the temperature-dependent conductivity shows that it may correspond from migration of doubly ionized oxygen vacancies. Impedance analysis shows a semicircular arc, that may correspond to thermally activated relaxation. Result from scanning electron microscopy (SEM) showed well-developed grains with an average size of about 4.26 & micro;m, suggesting Ce-induced grain coarsening beyond its solubility limit. In overall, the aliovalent substitution of Ce3+ for Ba2+ was found to influence defect chemistry and charge-compensation mechanisms, providing a route to tune both dielectric and electrical characteristics. These findings demonstrate that Ce-doped BaTiO3 offers promising potential as a lead-free ferroelectric material for capacitor and sensor technologies.
This study reports the synthesis and characterization of activated carbon (AC) derived from face mask waste using chemical activation subsequent carbonization at temperatures varied between 650-850 degrees C. The structural, morphological, and electrical properties of the resulting AC were probed using Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), and electrical potential measurement of the AC electrode. The findings show that the structural, morphological, and electrical characteristics of the AC are strongly influenced by the carbonization temperature. The existence of functional groups-graphitic carbon, and carbonaceous materials was demonstrated by FTIR and Raman studies, respectively. The sample carbonized at 650 degrees C exhibited the highest degree of disorder, a fibrous porous structure, and the greatest carbon content. Notably, this sample demonstrated the highest voltage output (35 mV) when employed as an electrode in a supercapacitor, indicating superior energy storage capability. This study emphasizes the potential of converting face mask waste into functional AC for sustainable energy storage applications, specifically supercapacitors.
This work proposes a novel gate-engineered Mid-Insulation Gate Junctionless Transistor (MiG-JLT) and presents a comparative performance evaluation against the conventional Symmetric Double Gate Junctionless Transistor (SDG-JLT). Under identical physical parameters, the proposed MiG-JLT demonstrates a nearly 35% enhancement in ON-state current, achieving an ON current of approximately 2.5 x 10(-5) A and an I-ON/I-OFF ratio of about 2.5 x 10(8). For a silicon body thickness of 10 nm, the device exhibits a peak transconductance of similar to 7 x 10(-5) S, and a drain conductance of similar to 1.3 x 10(-4) S at low drain bias, confirming its improved analog performance. The effects of doping concentration, surface potential distribution, and channel width are systematically analyzed. Circuit-level inverter analysis further demonstrates enhanced transfer and switching characteristics. Overall, the proposed MiG-JLT shows strong potential for high-performance nanoscale and SPICE-compatible device applications.
The knit structure is the primary factor that influences the moisture management properties and liquid transport in sportswear fabrics. Four polyester microfibre sports jersey fabrics were characterised by their fibre composition using Fourier Transform Infrared Spectroscopy (FTIR), and their moisture management performance was assessed in terms of absorption rate, wetting time, spreading speed, maximum wetted radius, Accumulative One-way Transport Index (AOTI), and Overall Moisture Management Capability (OMMC). Results showed that different knit structures had a noticeable impact on overall moisture management, with polar eyelet fabric showing faster surface wetting, a larger wetted radius on the bottom surface, and higher spreading speeds on the top and bottom surfaces of the fabrics. Statistical analysis using one-way ANOVA and Tukey's HSD showed significant differences between the fabrics in terms of spreading speed, wetted radius, AOTI, and OMMC. Overall, the polar eyelet fabric offered rapid surface wetting and spreading, while the interlock fabric performed better in one-way moisture transfer.
Gate oxide uniformity is very important to the electrical wafer test performance such as Breakdown Voltage (B-VDSS), Gate Source Leakage Current (I-GSS), Gate Charge and reliability for vertical trench MOSFETs (U-MOSFETs), particularly in advanced scaling designs with compact cell layouts for lower Drain Source On Resistance (R-DSON). This study investigates gate oxide formation in a high-density N-type 30V UMOSFET with a 0.8 & micro;m cell pitch from Product B. Conventional dry oxidation produces non-uniform oxide thickness, especially at the trench corners, leading to degradation of the B-VDSS and leakage characteristics (I-GSS). To address this, we propose a multi-layer thermal oxidation process combining the dry and wet oxidation, achieving improved corner coverage while maintaining a target gate oxide thickness of 500 & Aring;. Transmission electron microscopy (TEM) analysis confirms that the multi-layer thermal oxidation (dry and wet oxidation) method reduces thickness variation from more than 25% to less than 10% compared to pure dry oxidation. Electrical characterization shows enhanced B-VDSS, I-GSS and stable threshold voltage (V-TH) without impacting (R-DSON). These results demonstrate that the proposed multi-layer thermal oxidation process is an effective approach for fabricating robust gate oxides in next-generation, scaled power MOSFETs. It is suggested that trench depth and P-body doping are further optimized to improve the balance between breakdown voltage and threshold voltage.
This study investigates the co-sensitization of natural dyes with synthetic dye N719 in dye-sensitized solar cells (DSSCs). Natural dyes from Spinacia oleracea (green spinach) and Plumeria rubra (frangipani) were extracted and analyzed via UV-Visible spectroscopy to assess their light absorption capabilities. Co-sensitization was carried out by blending these extracts with N719, aiming to broaden the absorption spectrum and improve overall efficiency. The impact of titanium dioxide (TiO2) photoanode thickness (55,000 nm and 110,000 nm) and different substrates (indium tin oxide and fluorine-doped tine oxide) on the power conversion efficiency (PCE) was systematically studied under controlled fabrication conditions using 4 different cases (Case A, Case B, Case C, and Case D). Among the four dye combinations tested, the N719-frangipani co-sensitized DSSC fabricated on FTO glass with a 110,000 nm TiO2 layer demonstrated the highest PCE of 0.0324%. In contrast, the lowest performance (0.000014%) was observed in the cell sensitized with a spinach-frangipani blend on ITO. UV-Visible spectral analysis confirmed broader light absorption for co-sensitized dyes, while I-V characterization revealed enhanced charge transport in thicker photoanodes and FTO-based cells. These findings demonstrate the potential of co-sensitization using natural dyes to partially replace synthetic dyes, offering a cost-effective and environmentally friendly approach to DSSC fabrication.
The treatment of diabetic wounds remains a global challenge, as their nature of delayed healing, which is due to the oxidative stress, persistent infection, and frequent dressing changes during the healing process, could risk limb amputations and even fatality. A variety of approaches have been undertaken to generate skin substitutes, wound-healing patches, or dressings with adequate barrier properties, degradation, exudate uptake capacity, and wound-healing capacity. This study aimed to evaluate a novel bioactive wound dressing from rice husk cellulose acetate (CA) electrospun loaded with kaempferol (KM) and layered with alginate solution (CAKM/ALG) with the ability to deliver KM to the wound site. KM is highly enriched with multiple therapeutic agents that can promote cellular response and wound healing. In this study, electrospun CA nanofibers containing KM were first fabricated by the electrospinning method and then combined with the alginate hydrogel (ALG). The scanning electron microscopy images and macroscopic images revealed that CA nanofibers were fully covered with alginate hydrogel. FTIR results showed the successful incorporation of KM in nanofibers. Water contact angle, porosity, water uptake, and weight loss study of CA-KM/ALG (0 degrees, 91.30 +/- 4.72%, 600-650%, 50%). Fibroblast culturing on the fabricated dressings in both normal and hyperglycemic conditions demonstrated that cellular attachment and proliferation improved with suitable KM concentration (15.67 & micro;g/mL). Taken together, our results provide a novel bioactive dressing with great potential for speeding up the healing process in severe wounds.
