Publications Archives – Institute of Nano Electronic Engineering

Graphene Nanoplatelets Suppress Foam Cell Formation and Atherogenic Inflammation in Macrophages

June 18, 2026 By Editor

Abstract – Scope: Foam cell formation is a hallmark of early atherosclerosis, driving plaque development and chronic vascular inflammation. These lipid-engorged macrophages form through excessive uptake of oxidised low-density lipoprotein (oxLDL) and play a central role in disease progression. Graphene nanoplatelets (GNPs), known for their high surface area and biocompatibility, have emerged as promising nanomaterials for biomedical intervention. This study evaluates the potential of GNPs to prevent atherosclerosis by targeting foam cell formation. Methods: Computational analyses, including molecular docking and dynamics simulations, were used to assess the binding affinity of GNPs with key atherogenic proteins such as apolipoprotein B and the LDL receptor. GNPs were structurally characterised using Raman spectroscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. In vitro assays were conducted on RAW264.7 macrophages to assess cytotoxicity, lipid accumulation, cholesterol levels, cytokine production, and gene expression after treatment with GNPs (1 μg/mL) and oxLDL. Results: GNPs exhibited strong binding affinity to apoB and the LDL receptor, suggesting potential interference with lipid uptake. Structural analyses confirmed the integrity and purity of the GNPs. In vitro, GNPs showed no cytotoxic effects and significantly reduced lipid accumulation and intracellular cholesterol levels in oxLDL-treated macrophages. They also suppressed the secretion of pro-inflammatory cytokines (IFNγ, IL-6, IL-1β) and downregulated genes associated with foam cell formation (IL-1β, ACAT-1, CD36), while upregulating ABCA1, a key gene involved in cholesterol efflux. Conclusion: These findings demonstrate that GNPs effectively inhibit foam cell formation, reduce atherogenic inflammation, and enhance lipid clearance in macrophages. GNPs represent a promising nanotherapeutic strategy for the prevention of atherosclerosis.

Author: Assoc. Prof. Ir. Ts. Dr. Muhammad Mahyiddin Ramli
Author’s Email: mmahyiddin@unimap.edu.my

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Link to Publication: https://link.springer.com/article/10.1007/s12195-026-00899-w

Fabrication and simulation of silicon nanogaps pH sensor as preliminary study for Retinol Binding Protein 4 (RBP4) detection

March 1, 2025 By Editor

Abstract – In this research, a silicon nanogap biosensor has the potential to play a significant role in the field of biosensors for detecting Retinol Binding Protein 4 (RBP4) molecules due to its unique nanostructure morphology, biocompatibility features, and electrical capabilities. Additionally, as preliminary research for RBP4, a silicon nanogap biosensor with unique molecular gate control for pH measurement was developed. Firstly, using conventional lithography followed by the Reactive-ion etching (RIE) technique, a nanofabrication approach was utilized to produce silicon nanogaps from silicon-on-insulator (SOI) wafers. The critical aspects contributing to the process and size reduction procedures were highlighted to achieve nanometer-scale size. The resulting silicon nanogaps, ranging from 100 nm to 200 nm, were fabricated precisely on the device. Secondly, pH level detection was performed using several types of standard aqueous pH buffer solutions (pH 6, pH 7, pH 12) to test the electrical response of the device. The sensitivity of the silicon nanogap pH sensor was 7.66 pS/pH (R² = 0.97), indicating that the device has a wide range of pH detecting capacity. This also includes the silicon nanogap biosensor validated by simulation, with the sensitivity obtained being 3.24 μA/e.cm² (R² = 0.98). The simulation of the sensitivity is based on the interface charge (Qf) that represents the concentration of RBP4. The results reveal that the silicon nanogap biosensor has excellent characteristics for detecting pH levels and RBP4 with outstanding sensitivity performance. In conclusion, this silicon nanogap biosensor can be used as a new electrical RBP4 biosensor for biomedical diagnostic applications in the future.

Corresponding Author: Assoc. Prof. Dr. Mohammad Nuzaihan Md Nor
Corresponding Author’s Email: m.nuzaihan@unimap.edu.my

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Link to Publication: https://doi.org/10.58915/ijneam.v17iJune.830

Comparative Analysis on Aluminium Interdigitated Electrode Surface: Influence of Ionic Strength and Electrolytes Changes

December 5, 2024 By Editor

Abstract – The field of generating surface thin films in sensing applications is emerging, and the incorporation of thin film technology into sensor development for enhanced sensing is becoming increasingly significant in various industries such as healthcare, environmental monitoring, and food safety. However, in order to achieve higher specificity in biosensing, advances in nanomaterial biofunctionalization are crucial. This research focuses on the fabrication and characterization of nanobiosensors with surface modification using two different sensing materials: zinc oxide and gold nanorod nanocomposites. The aim of this study was to enhance the sensing capabilities of nanobiosensors by incorporating surface modification with different sensing materials. The fabrication of nanobiosensors involved using silicon as the base material and conventional photolithography to fabricate aluminium interdigitated electrodes with three different structures and gap sizes. AutoCAD software was utilized to create three different photo masks with varying gap sizes. Physical characterization of the fabricated ALIDEs was conducted using atomic force microscope, high power microscope, scanning electron microscope, and 3D-profilormeter. The electrical characterization of the ALIDEs was performed using a Keithley 6487 picoammeter. I-V measurements were conducted on bare ALIDEs as well as surface modified ALIDEs with zinc oxide and gold nanorod. I-V measurements were also performed for pH scouting. The I-V measurements on bare ALIDEs revealed that ALIDEs modified with gold nanorod conducted the least current compared to ALIDEs modified with zinc oxide. Furthermore, the ALIDEs modified with gold nanorod were found to be stable under various electrolytes environments after undergoing pH scouting.

Corresponding Author: Prof. Dr. Subash C B Gopinath
Corresponding Author’s Email: subash@unimap.edu.my

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Link to Publication: https://doi.org/10.58915/ijneam.v17iJune.8 30

Chitosan-mediated tailoring of cadmium sulphide nanoparticle: Synthesis, properties, and interactive mechanisms

June 10, 2024 By Editor

Abstract – This study explores the synergistic effects of chitosan-coated cadmium sulphide (CdS) nanoparticles (NPs) at varying concentrations on their structural, optical, and photocatalytic properties. CdS NPs are known for their promising photocatalytic potential, but their practical application often requires stability enhancement and reduced toxicity. Chitosan, a natural biopolymer, offers unique advantages such as biocompatibility and heavy metal adsorption capabilities, making it an attractive candidate for surface modification of CdS NPs. Our investigation reveals that chitosan-coated CdS NPs exhibit concentration-dependent changes in their crystalline structure, bandgap energy, particle size, and vibrational characteristics. Notably, CdS NPs synthesized with 1.5 g chitosan concentration display the smallest bandgap and particle size, suggesting optimal photocatalytic activity. This research provides valuable insights into tailoring CdS NPs for efficient visible light photocatalysis, with implications in environmental remediation and energy conversion.

Corresponding Author: Prof. Dr. Subash C B Gopinath
Corresponding Author’s Email: subash@unimap.edu.my

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Link to Publication: https://doi.org/10.1016/j.procbio.2024.05.01 4

Numerical Simulation on the Impact of Back Gate Voltage in Thin Body and Thin Buried Oxide of Silicon on Insulator (SOI) MOSFETs

December 1, 2023 By Editor

Abstract – Silicon-on-Insulator (SOI) technology provides a solution for controlling Short-Channel Effects (SCEs) and enhancing the performance of Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs). However, scaling down SOI MOSFETs to a nanometer scale does not necessarily yield further scaling benefits. Introducing multiple gates, such as a double gate configuration, can effectively mitigate SCEs. Nonetheless, fabricating a flawless double gate structure is an exceedingly challenging endeavor that remains unrealized. The adoption of a back gate bias, with an asymmetrical thickness arrangement between the front and back gates, mimicking the behavior of a double gate, offers an alternative approach. This approach has the potential to modify the electrical characteristics of the device, thus potentially leading to improved control over SCEs. In this study, we employed 2D simulations using Atlas to investigate the influence of back gate biases, namely, -2.0 V, 0 V, and 2.0 V on a 10 nm silicon thickness at the top and a 20 nm buried oxide thickness for n-channel MOSFETs. We focused on key parameters, including threshold voltage (VTh), Drain Induced Barrier Lowering (DIBL), and Subthreshold Swing (SS). The results demonstrate that a negative back gate bias is the most favorable configuration, as it yields superior performance. This translates into more effectively controlled SCEs across all the parameters of interest.

Corresponding Author: Dr. Mohamad Faris Mohamad Fathil
Corresponding Author’s Email: mohamadfaris@unimap.edu.my

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Link to Publication: https://ijneam.unimap.edu.my/index.php/vol-16-no-4-october-2023