Biosensor Archives – Institute of Nano Electronic Engineering

Faradaic electrochemical impedimetric analysis on MoS2/Au-NPs decorated surface for C-reactive protein detection

December 7, 2022 By Editor

Abstract – Background: A label-free Faradaic electrochemical impedimetric was developed for a highly sensitive detection of C-reactive protein using a gold interdigitated microelectrode bio-sensing platform enhanced by a gold nanoparticle-decorated molybdenum disulfide (Au-NPs/MoS2) nanosheet via selected chemical linking processes. C-reactive protein (C-RP), a crystalline protein, generates by the liver and hikes when there is inflammation throughout the patients’ body. The concentrations of C-RP plasma levels tend to increase rapidly when the patient facing major injury which will lead to cardiovascular disease (CVD). Methods: The 5 µm microelectrode and gap size g-IDE with the nanostructured materials was demonstrated to increase the impedimetric detection response in Faradaic-mode electrochemical impedance spectroscopy high performance detection environment. The high surface area-to-volume ratio of the modified Au-NPs/MoS2 nanocomposite increased the probes loading onto the transducer and enhanced the impedimetric detection response of the C-RP target post-binding due to an amplified net change in the charge transfer resistance. The developed immunoassay revealed a linear detection of C-RP biomarker in a logarithmic-scale from as low as 1 fg/mL up to 1 µg/mL, and a limit of detection of 0.01 fg/mL. The sensor shows great potential as an early warning risk for cardiovascular disease at a threshold concentration value of C-RP at 1 µg/mL. Significant findings: The biosensor demonstrates an excellent discrimination against other competing proteins in serum, exhibiting the highest predilection to C-RP spiked human serum target. The sensor’s reproducibility is reported within an acceptable range of relative standard deviation of 1–4% for n = 3.

Corresponding Author: Assoc. Prof. Ir. Dr. Mohd Khairuddin Md Arshad
Corresponding Author’s Email: mohd.khairuddin@unimap.edu.my

Download Abstract: PDF
Link to Publication: https://doi.org/10.1016/j.jtice.2022.104450

Congratulations to Assoc. Prof. Ir. Dr. Mohd Khairuddin and team for a publication in Current Medicinal Chemistry

June 22, 2020 By Editor

Congratulations to Ms. Iswary Letchumanan (Ph.D student under PE18 – Nanobiotechnology Engineering Programme), Assoc. Prof. Ir. Dr. Mohd Khairuddin Md A, Assoc. Prof. Dr. Subash Gopinath for a new review article publication in Current Medicinal Chemistry entitled “Nanodiagnostic Attainments and Clinical Perspectives on C-Reactive Protein: Cardiovascular Disease Risks Assessment”.

I. Letchumanan, M. K. M. Arshad, and S. C. B. Gopinath, “Nanodiagnostic Attainments and Clinical Perspectives on C-Reactive Protein: Cardiovascular Disease Risks Assessment,” Curr. Med. Chem., vol. 27, Jan. 2020.

Design and fabrication of PDMS microfluidics device for rapid and label-free DNA detection

March 24, 2020 By Editor

Abstract – Microfluidics explores the manipulation of fluid in small volume, a multidisciplinary field is imperative for DNA extraction. This study offers a simple yet substantial methodology for the fabrication of microfluidics structure-based polydimethylsiloxane (PDMS) biopolymer on a glass substrate with SU-8 photoresist for label-free detection of pathogenic genomic DNA. Two microfluidics designs for DNA detection were based on AutoCAD software, both contain two inlets and one outlet, with dimensions of 28 mm wide, and 18 mm long, and total surface area of 504 mm2. The designs were patterned in such particular sizes and dimensions to test fluid delivery and enhancement in biochemical processes in DNA extraction, while maintaining economical values as a disposable chip. Both microfluidics devices showed no leakage during fluid delivery, have heights of 97.97 and 103.44 μm, and surface roughness of 0.15 and 0.07 μm, respectively. DNA extraction from pathogenic fungus Ganoderma boninense was run on PDMS microfluidic device and UV–Vis analysis confirmed successful extraction with peaks found at 260–280 nm. Current–voltage (I–V) measurement confirmed the accuracy of microfluidic device for the specific pathogen with both real and synthetic samples of G. boninense illustrating the similar graph values of only 0.000005 A difference at 1.0 V after hybridization.

Corresponding Author: Prof. Dr. Uda Hashim
Corresponding Author’s Email: uda@unimap.edu.my

Download Abstract: PDF

Substrate-gate coupling in ZnO-FET biosensor for cardiac troponin I detection

March 17, 2017 By Editor

Abstract – Currently, field-effect transistor (FET)-based biosensors have been implemented in several portable sensors with the ultimate application in point-of-care testing (POCT). In this paper, we have designed substrate-gate coupling in FET-based biosensor for the detection of cardiac troponin I (cTnI) biomarker. In the device structure, zinc oxide nanoparticles (ZnO-NPs) thin film were deposited through sol-gel and spin coating techniques on the channel. The p-type silicon was used as a substrate, while ZnO is an n-type nanomaterial, thus creates p-n-p junction between source, channel, and drain. The deposited thin films exhibited hexagonal wurtzite phase of ZnO, suitable for biomolecular interaction as revealed in X-ray diffraction (XRD) analysis. The surface of the thin film was then functionalized with 3-aminopropyltriethoxysilane (APTES), followed by glutaraldehyde (GA) as a bi-functional linker to immobilize the cTnI monoclonal antibody (MAb-cTnI) as bio-receptor for capturing cTnI biomarker and proven by the Fourier transform-infrared (FT-IR) spectra. Lastly, we demonstrated a new strategy, the integration of FET-based biosensors with substrate-gate showed differences between before (immobilization) and after cTnI target biomarker interaction by significant changes in drain current (ID) and change of threshold voltage (VT), which improved the sensitive detection, with the limit of detection down to 3.24 pg/ml.

Keywords – Biosensor, Cardiac troponin I, Electrical-based, Field-effect transistor, Substrate-gate coupling, Zinc oxide nanoparticles

Corresponding Author: Uda Hashim
Corresponding Author’s Email: uda@unimap.edu.my

Full text: PDF

2-Day Course on Nano-Biosensor

October 17, 2014 By Editor

Date: November 24 & 25, 2014
Time: 9.00 a.m. – 5 p.m.
Venue: Institute of Nano Electronic Engineering, UniMAP

Course Background

Biosensor is a short form for “biological sensor”. The device is made up of a transducer and a biological element that may be an enzyme, an antibody or a nucleic acid. The bio-element interacts with the analyte being tested and the biological response is converted into an electrical signal by the transducer. Depending on their particular application, biosensors are also known as immunosensors, optrodes, resonant mirrors, chemical canaries, biochips, glucometers and biocomputers.

The Objectives

Provide an overview on the important aspects and principles of nano biosensor design, fabrication and characterization.
Assist the participants in understanding major fabrication steps and their underlying theories.
Exposure to the sophisticated and state-of-the art nano devices fabrication equipment and tools.

Any inquiry, kindly contact:
Dr Ramzan b Mat Ayub
Mobile: +6012-274 9986
Email: ramzan@unimap.edu.my