Displaying publications 1 - 20 of 37 in total

Abstract:
Sort:
  1. Discovery of indoleninyl-pyrazolo[3,4-b]pyridines as potent chemotherapeutic agents against colorectal cancer cells
    Basir NH, Ramle AQ, Ng MP, Tan CH, Tiekink ERT, Sim KS, et al.
    Bioorg Chem, 2024 May;146:107256.
    PMID: 38460334 DOI: 10.1016/j.bioorg.2024.107256
    A new series of indolenines decorated with pyrazolo[3,4-b]pyridines were designed and synthesized in up to 96% yield from the acid-catalyzed cyclocondensation of 1,3-dialdehydes with 3-aminopyrazoles. X-ray crystallography on a representative derivative, 5n, revealed two close to planar conformations whereby the N-atom of the pyridyl residue was syn or anti to the pyrrole-N atom in the two independent molecules of the asymmetric unit. The computational and DNA binding data suggest that 5n is a strong DNA intercalator with the results in agreement with its potent cytotoxicity against two colorectal cancer cell lines (HCT 116 and HT-29). In contrast to doxorubicin, compounds 5k-o have higher druggability (compliance to more criteria stated in Lipinski's rule of five and Veber's rule), higher bioavailability, and better medicinal chemistry properties, indicative of their potential application as chemotherapeutical agents.
  2. Electrochemical assisted enhanced nanozymatic activity of functionalized borophene for H2O2 and tetracycline detection
    Ahmed SR, Sherazee M, Das P, Shalauddin M, Akhter S, Basirun WJ, et al.
    Biosens Bioelectron, 2024 Feb 15;246:115857.
    PMID: 38029708 DOI: 10.1016/j.bios.2023.115857
    This study unveils the electrochemically-enhanced nanozymatic activity exhibited by borophene during the reaction of 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2. Herein, the surface of the pristine borophene was first modified with the addition of thiocyanate groups to improve hydroxyl radical (•OH) scavenging activity. Then, the oxidation reaction of TMB was accelerated under applied electrochemical potential. Both factors significantly improved the detection limit and drastically decreased the detection time. DPPH testing revealed that the radical scavenging nature of borophene was more than 70%, boosting its catalytic activity. In the presence of H2O2, borophene catalyzed the oxidation of TMB and produced a blue-colored solution that was linearly correlated with the concentration of H2O2 and allowed for the detection of H2O2 up to 38 nM. The present finding was further extended to nanozymatic detection of tetracyclines (TCs) using a target-specific aptamer, and the results were colorimetrically quantifiable up to 1 μM with a LOD value of 150 nM. Moreover, transferring the principles of the discussed detection method to form a portable and disposable paper-based system enabled the quantification of TCs up to 0.2 μM. All the sensing experiments in this study indicate that the nanozymatic activity of borophene has significantly improved under electrochemical potential compared to conventional nanozyme-based colorimetric detection. Hence, the present discovery of electrochemically-enhanced nanozymatic activity would be promising for various sensitive and time-dependent colorimetric sensor development initiatives in the future.
  3. Fulltext Catalytic activity of ethylbenzene with product selectivity by gold nanoparticles supported on zinc oxide
    Anwar A, Ma'amor A, Mahmud HNME, Basirun WJ, Abdullah I
    Turk J Chem, 2022;46(3):730-746.
    PMID: 37720623 DOI: 10.55730/1300-0527.3363
    The oxidation of ethylbenzene (EB) using tert-butyl hydroperoxide as the oxidizing agent was carried out in presence of gold nanoparticles (3 nm) supported on zinc oxide in acetonitrile solution. A higher selectivity towards acetophenone (ACP) as the major product, and a moderate selectivity towards other products such as 1-phenylethanol (PE), benzaldehyde (BZL), and benzoic acid (BzA) were observed using the prepared Au/ZnO nanocatalysts at 100 °C for 24 h. It is suggested the reaction produces an intermediate product, which is dimethylethyl-1-phenylethyl peroxide through a radical mechanism. A small amount of benzaldehyde was observed because benzaldehyde went autoxidation to form benzoic acid with the presence of oxidation agent of TBHP during reaction. The factors affecting the catalytic activity such as gold loading, calcination treatment at 300°C, type of solvent, reaction time, reaction temperature, oxidant to substrate molar ratio, catalyst weight, and solvent volume were studied. The gold nanoparticle catalyst synthesized by deposition precipitation method using urea was characterized by XRD, HRTEM, ATR-IR, XRF, and BET and offers a very selective reaction pathway for the oxidation of ethylbenzene.
  4. DNA/Nano based advanced genetic detection tools for authentication of species: Strategies, prospects and limitations
    Khalil I, Hashem A, Nath AR, Muhd Julkapli N, Yehye WA, Basirun WJ
    Mol Cell Probes, 2021 10;59:101758.
    PMID: 34252563 DOI: 10.1016/j.mcp.2021.101758
    Authentication, detection and quantification of ingredients, and adulterants in food, meat, and meat products are of high importance these days. The conventional techniques for the detection of meat species based on lipid, protein and DNA biomarkers are facing challenges due to the poor selectivity, sensitivity and unsuitability for processed food products or complex food matrices. On the other hand, DNA based molecular techniques and nanoparticle based DNA biosensing strategies are gathering huge attention from the scientific communities, researchers and are considered as one of the best alternatives to the conventional strategies. Though nucleic acid based molecular techniques such as PCR and DNA sequencing are getting greater successes in species detection, they are still facing problems from its point-of-care applications. In this context, nanoparticle based DNA biosensors have gathered successes in some extent but not to a satisfactory stage to mark with. In recent years, many articles have been published in the area of progressive nucleic acid-based technologies, however there are very few review articles on DNA nanobiosensors in food science and technology. In this review, we present the fundamentals of DNA based molecular techniques such as PCR, DNA sequencing and their applications in food science. Moreover, the in-depth discussions of different DNA biosensing strategies or more specifically electrochemical and optical DNA nanobiosensors are presented. In addition, the significance of DNA nanobiosensors over other advanced detection technologies is discussed, focusing on the deficiencies, advantages as well as current challenges to ameliorate with the direction for future development.
  5. Fulltext In-situ study of electrochemical migration of tin in the presence of bromide ion
    Lee EL, Haseeb ASMA, Basirun WJ, Wong YH, Sabri MFM, Low BY
    Sci Rep, 2021 Aug 03;11(1):15768.
    PMID: 34344974 DOI: 10.1038/s41598-021-95276-0
    The miniaturization of electronic devices and the consequent decrease in the distance between conductive lines have increased the risk of short circuit failure due to electrochemical migration (ECM). The presence of ionic contaminants affects the ECM process. This work systematically investigates the ECM of tin (Sn) in the presence of bromide ions (Br-) in the range of 10-6 M to 1.0 M. Water drop test (WDT) was conducted in the two-probe semiconductor characterization system under an optical microscope as an in-situ observation. Polarization test was carried out to study the correlation between the corrosion properties of Sn and its ECM behaviour. The products of ECM were characterized by scanning electron microscope coupled with an energy dispersive X-rays spectrometer (SEM/EDX) and X-ray photoelectron spectrometer (XPS). The results confirm that the rate of anodic dissolution of Sn monotonously increases with the Br- concentration. However, the probability of ECM failure follows a normal distribution initially, but later increases with the Br- concentration. The main products of the ECM reactions are identified as Sn dendrites and tin hydroxide precipitates. The mechanisms of the ECM process of Sn in the presence of Br- are also suggested.
  6. Fulltext Mixed oxide nanotubes in nanomedicine: A dead-end or a bridge to the future?
    Sarraf M, Nasiri-Tabrizi B, Yeong CH, Madaah Hosseini HR, Saber-Samandari S, Basirun WJ, et al.
    Ceram Int, 2021 Feb 01;47(3):2917-2948.
    PMID: 32994658 DOI: 10.1016/j.ceramint.2020.09.177
    Nanomedicine has seen a significant rise in the development of new research tools and clinically functional devices. In this regard, significant advances and new commercial applications are expected in the pharmaceutical and orthopedic industries. For advanced orthopedic implant technologies, appropriate nanoscale surface modifications are highly effective strategies and are widely studied in the literature for improving implant performance. It is well-established that implants with nanotubular surfaces show a drastic improvement in new bone creation and gene expression compared to implants without nanotopography. Nevertheless, the scientific and clinical understanding of mixed oxide nanotubes (MONs) and their potential applications, especially in biomedical applications are still in the early stages of development. This review aims to establish a credible platform for the current and future roles of MONs in nanomedicine, particularly in advanced orthopedic implants. We first introduce the concept of MONs and then discuss the preparation strategies. This is followed by a review of the recent advancement of MONs in biomedical applications, including mineralization abilities, biocompatibility, antibacterial activity, cell culture, and animal testing, as well as clinical possibilities. To conclude, we propose that the combination of nanotubular surface modification with incorporating sensor allows clinicians to precisely record patient data as a critical contributor to evidence-based medicine.
  7. A review of gas chromatographic techniques for identification of aqueous amine degradation products in carbonated environments
    Saeed IM, Mazari SA, Alaba P, Ali BS, Jan BM, Basirun WJ, et al.
    Environ Sci Pollut Res Int, 2021 Feb;28(6):6324-6348.
    PMID: 33398750 DOI: 10.1007/s11356-020-11753-5
    Degradation of amines is a significant issue allied to amine-based carbon dioxide (CO2) absorption in post-combustion CO2 capture. It becomes essential to have a detailed understanding of degradation products for advanced post-combustion CO2 capture technology. Identification and quantification of degradation products of amines help in practicability and environmental assessment of amine-based technology. Gas, liquid, and ion chromatographic techniques are the benchmark tools for qualitative and quantitative analyses of the amines and their derivatives. Among others, gas chromatography has been more in use for this specific application, especially for the identification of degradation products of amines. This review focuses on the critical elucidation of gas chromatographic analysis and development of methods to determine the amine degradation products, highlighting preparation methods for samples and selecting columns and detectors. The choice of detector, column, sample preparation, and method development are reviewed in this manuscript, keeping in view the industry and research applications. Furthermore, obtained results on the quantitative and qualitative analyses using gas chromatography are summarized with future perspectives.
  8. Recent advances in tissue engineering scaffolds based on polyurethane and modified polyurethane
    Naureen B, Haseeb ASMA, Basirun WJ, Muhamad F
    Mater Sci Eng C Mater Biol Appl, 2021 Jan;118:111228.
    PMID: 33254956 DOI: 10.1016/j.msec.2020.111228
    Organ repair, regeneration, and transplantation are constantly in demand due to various acute, chronic, congenital, and infectious diseases. Apart from traditional remedies, tissue engineering (TE) is among the most effective methods for the repair of damaged tissues via merging the cells, growth factors, and scaffolds. With regards to TE scaffold fabrication technology, polyurethane (PU), a high-performance medical grade synthetic polymer and bioactive material has gained significant attention. PU possesses exclusive biocompatibility, biodegradability, and modifiable chemical, mechanical and thermal properties, owing to its unique structure-properties relationship. During the past few decades, PU TE scaffold bioactive properties have been incorporated or enhanced with biodegradable, electroactive, surface-functionalised, ayurvedic products, ceramics, glass, growth factors, metals, and natural polymers, resulting in the formation of modified polyurethanes (MPUs). This review focuses on the recent advances of PU/MPU scaffolds, especially on the biomedical applications in soft and hard tissue engineering and regenerative medicine. The scientific issues with regards to the PU/MPU scaffolds, such as biodegradation, electroactivity, surface functionalisation, and incorporation of active moieties are also highlighted along with some suggestions for future work.
  9. Fabrication and Characterization of SnO-Cu₂O Mixed Metal Oxide Thin Films for Photoelectrochemical Applications
    Ahmed S, Shahid MM, Bakar SA, Arshed N, Basirun WJ, Fouad H
    J Nanosci Nanotechnol, 2020 12 01;20(12):7705-7709.
    PMID: 32711646 DOI: 10.1166/jnn.2020.18570
    Herein, we report the synthesis of SnO, Cu₂O and SnO-Cu₂O mixed oxide thin films on fluorinedoped tin oxide (FTO) substrate by Aerosol-Assisted Chemical Vapour Deposition (AACVD) process using [Cu (dmae)₂(H₂O)] and [Sn (dmae) (OAc)]₂ as molecular precursors for SnO and Cu₂O, respectively at 400 °C. The X-ray diffraction (XRD) pattern can be ascribed to the tetragonal phase of SnO crystals with space group P4 and cubic phase of Cu₂O crystals with space group Pn- 3m/nmm, respectively. The surface morphology characteristics of SnO, Cu₂O and SnO-Cu₂Omixed oxide have been investigated using Field Emission Scanning Electron Microscope (FESEM) which revealed that the SnO was grown homogeneously in cubical shape while Cu₂O possess nano balls shaped morphologies. The UV band gap values of SnO-Cu₂O mixed oxide thin film was found to be 2.6 eV appropriate for photoelectrochemical (PEC) applications. The synthesized material was proposed for PEC applications and has shown enhanced catalytic performance in the presence of light.
  10. Dual platform based sandwich assay surface-enhanced Raman scattering DNA biosensor for the sensitive detection of food adulteration
    Khalil I, Yehye WA, Muhd Julkapli N, Sina AA, Rahmati S, Basirun WJ, et al.
    Analyst, 2020 Feb 17;145(4):1414-1426.
    PMID: 31845928 DOI: 10.1039/c9an02106j
    Surface enhanced Raman scattering (SERS) DNA biosensing is an ultrasensitive, selective, and rapid detection technique with the ability to produce molecule-specific distinct fingerprint spectra. It supersedes the long amplicon based PCR assays, the fluorescence and spectroscopic techniques with their quenching and narrow spectral bandwidth, and the electrochemical detection techniques using multiplexing. However, the performance of the SERS DNA biosensor relies on the DNA probe length, platform composition, both the presence and position of Raman tags and the chosen sensing strategy. In this context, we herein report a SERS biosensor based on dual nanoplatforms with a uniquely designed Raman tag (ATTO Rho6G) intercalated short-length DNA probe for the sensitive detection of the pig species Sus scrofa. In the design of the signal probe (SP), a Raman tag was incorporated adjacent to the spacer arm, followed by a terminal thiol modifier, which consequently had a strong influence on the SERS signal enhancement. The detection strategy involves the probe-target DNA hybridization mediated coupling of the two platforms, i.e., the graphene oxide-gold nanorod (GO-AuNR) functionalized capture probe (CP) and SP-conjugated gold nanoparticles (AuNPs), consequently enhancing the SERS intensity by both the electromagnetic hot spots generated at the junctions or interstices of the two platforms and the chemical enhancement between the AuNPs and the adsorbed intercalated Raman tag. This dual platform based SERS DNA biosensor exhibited outstanding sensitivity in detecting pork DNA with a limit of detection (LOD) of 100 aM validated with DNA extracted from a pork sample (LOD 1 fM). Moreover, the fabricated SERS biosensor showed outstanding selectivity and specificity for differentiating the DNA sequences of six closely related non-target species from the target DNA sequences with single and three nucleotide base-mismatches. Therefore, the developed short-length DNA linked dual platform based SERS biosensor could replace the less sensitive traditional methods of pork DNA detection and be adopted as a universal detection approach for the qualitative and quantitative detection of DNA from any source.
  11. Rapid Nucleation of Reduced Graphene Oxide-Supported Palladium Electrocatalysts for Methanol Oxidation Reaction
    Ng JC, Tan CY, Ong BH, Matsuda A, Basirun WJ, Tan WK, et al.
    J Nanosci Nanotechnol, 2019 Nov 01;19(11):7236-7243.
    PMID: 31039881 DOI: 10.1166/jnn.2019.16717
    Small sized electrocatalysts, which can be obtained by rapid nucleation and high supersaturation are imperative for outstanding methanol oxidation reaction (MOR). Conventional microwave synthesis processes of electrocatalysts include ultrasonication, stirring, pH adjustment, and microwave irradiation of the precursor mixture. Ethylene glycol (EG), which serves as a reductant and solvent was added during the ultrasonication or stirring stage. However, this step and pH adjustment resulted in unintended multi-stage gradual nucleation. In this study, the microwave reduction approach was used to induce rapid nucleation and high supersaturation in order to fabricate small-sized reduced graphene oxide-supported palladium (Pd/rGO) electrocatalysts via the delayed addition of EG, elimination of the pH adjustment step, addition of sodium carbonate (Na₂CO₃), prior microwave irradiation of the EG mixed with Na₂CO₃, and addition of room temperature precursor mixture. Besides its role as a second reducing agent, the addition of Na₂CO₃ was primarily intended to generate an alkaline condition, which is essential for the high-performance of electrocatalysts. Moreover, the microwave irradiation of the EG and Na₂CO₃ mixture generated highly reactive free radicals that facilitate rapid nucleation. Meanwhile, the room temperature precursor mixture increased supersaturation. Results showed improved electrochemically active surface area (78.97 m² g-1, 23.79% larger), MOR (434.49 mA mg-1, 37.96% higher) and stability.
  12. Voltammetric sensing of formaldehyde by using a nanocomposite prepared by reductive deposition of palladium and platinum on polypyrrole-coated nitrogen-doped reduced graphene oxide
    Mahmoudian MR, Basirun WJ, Woi PM, Hazarkhani H, Alias YB
    Mikrochim Acta, 2019 05 22;186(6):369.
    PMID: 31119482 DOI: 10.1007/s00604-019-3481-y
    The study presents the synthesis of polypyrrole-coated palladium platinum/nitrogen-doped reduced graphene oxide nanocomposites (PdPt-PPy/N-rGO NC) via direct the reduction of Pd(II) and Pt(II) in the presence of pyrrole monomer, N-rGO and L-cysteine as the reducing agent. X-ray diffraction confirmed the presence of metallic Pd and Pt from the reduction of Pd and Pt cations. Transmission electron microscopy images revealed the presence of Pd, Pt and PPy deposition on N-rGO. Impedance spectroscopy results gave a decreased charge transfer resistance due to the presence of N-rGO. The nanocomposites were synthesized with different Pd/Pt ratios (2:1, 1:1 and 1:2). A glassy carbon electrode (GCE) modified with the nanocomposite showed enhanced electrochemical sensing capability for formaldehyde in 0.1 M sulfuric acid solution. Cyclic voltammetry showed an increase in the formaldehyde oxidation peak current at the GCE modified with Pd2Pt1 PPy N-rGO. At a typical potential of 0.45 V (vs. SCE), the sensitivity in the linear segment was 345.8 μA.mM -1. cm-2. The voltammetric response was linear between 0.01 and 0.9 mM formaldehyde concentration range, with a 27 µM detection limit (at S/N = 3). Graphical abstract Schematic presentation of formaldehyde detection by Pd2Pt1-PPy/nitrogen-doped reduced Graphene Oxide Nanocomposite (Pd2Pt1-PPy /N-Gr NC). The decrease of charge transfer resistance and the agglomeration of deposited metals in the presence of N-rGO enhance the current response of the electrochemical sensor.
  13. Graphene oxide and gold nanoparticle based dual platform with short DNA probe for the PCR free DNA biosensing using surface-enhanced Raman scattering
    Khalil I, Yehye WA, Julkapli NM, Rahmati S, Sina AA, Basirun WJ, et al.
    Biosens Bioelectron, 2019 Apr 15;131:214-223.
    PMID: 30844598 DOI: 10.1016/j.bios.2019.02.028
    Surface-enhanced Raman scattering (SERS) based DNA biosensors have considered as excellent, fast and ultrasensitive sensing technique which relies on the fingerprinting ability to produce molecule specific distinct spectra. Unlike conventional fluorescence based strategies SERS provides narrow spectral bandwidths, fluorescence quenching and multiplexing ability, and fitting attribute with short length probe DNA sequences. Herein, we report a novel and PCR free SERS based DNA detection strategy involving dual platforms and short DNA probes for the detection of endangered species, Malayan box turtle (MBT) (Cuora amboinensis). In this biosensing feature, the detection is based on the covalent linking of the two platforms involving graphene oxide-gold nanoparticles (GO-AuNPs) functionalized with capture probe 1 and gold nanoparticles (AuNPs) modified with capture probe 2 and Raman dye (Cy3) via hybridization with the corresponding target sequences. Coupling of the two platforms generates locally enhanced electromagnetic field 'hot spot', formed at the junctions and interstitial crevices of the nanostructures and consequently provide significant amplification of the SERS signal. Therefore, employing the two SERS active substrates and short-length probe DNA sequences, we have managed to improve the sensitivity of the biosensors to achieve a lowest limit of detection (LOD) as low as 10 fM. Furthermore, the fabricated biosensor exhibited sensitivity even for single nucleotide base-mismatch in the target DNA as well as showed excellent performance to discriminate closely related six non-target DNA sequences. Although the developed SERS biosensor would be an attractive platform for the authentication of MBT from diverse samples including forensic and/or archaeological specimens, it could have universal application for detecting gene specific biomarkers for many diseases including cancer.
  14. Molybdenum disulfide nanosheet decorated with silver nanoparticles for selective detection of dopamine
    Sookhakian M, Basirun WJ, Goh BT, Woi PM, Alias Y
    Colloids Surf B Biointerfaces, 2019 Apr 01;176:80-86.
    PMID: 30594706 DOI: 10.1016/j.colsurfb.2018.12.058
    A metal-inorganic composite, comprises of silver-molybdenum disulfide nanosheets (Ag@MoS2) was synthesized at low temperature. The Ag@MoS2 composite was drop-casted onto a glassy carbon electrode (GCE) for a highly selective dopamine (DA) detection in the presence of interfering compounds such as uric acid (UA) and ascorbic acid (AA). The physicochemical analysis of the nanosheets was carried out with X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy. The as-prepared Ag@MoS2-modified GCE displayed excellent electrocatalytic activity toward DA oxidation, with a 0.2 μM detection limit at a signal-to-noise ratio of 3 and an extensive linear detection range from 1 μM to 500 μM (R2 = 0.9983). The fabricated non-enzymatic electrochemical sensor demonstrated superior selectivity and stability for the detection of DA with the removal of AA and UA interfering compounds.
  15. Mesoporous silica from batik sludge impregnated with aluminum hydroxide for the removal of bisphenol A and ibuprofen
    Choong CE, Ibrahim S, Basirun WJ
    J Colloid Interface Sci, 2019 Apr 01;541:12-17.
    PMID: 30682589 DOI: 10.1016/j.jcis.2019.01.071
    The present study reports the removal of Bisphenol A (BPA) and Ibuprofen (IBP) using adsorbents prepared from batik sludge. The calcite sludge-aluminum hydroxide (CAl) adsorbent was prepared by calcination and followed by aluminum hydroxide impregnation. The batik sludge and prepared adsorbents were characterized by FESEM, TGA, XRD, FTIR and BET techniques. The maximum adsorption capacity, adsorption time, different initial solution pH, ionic strength and regeneration study of the adsorbents were also investigated. Furthermore, the sorption behavior of the pollutants were studied by the Langmuir and Freundlich isotherms. The deposition of Al(OH)3 enhanced the BPA and IBP adsorption capacity on the CAl surface. The maximum removal capacity of BPA and Ibuprofen were 83.53 mg g-1 and 34.96 mg g-1 for the CAl adsorbent. In addition, the kinetic data for BPA and IBP were fitted to the pseudo first order, pseudo second order, Elovich, parabolic diffusion and power function equations to understand the sorption behavior. The adsorption behavior of BPA and IBP was mainly chemisorption. This study shows that CAl is a promising adsorbent for the removal of BPA and IBP.
  16. Facile and greener hydrothermal honey-based synthesis of Fe3 O 4 /Au core/shell nanoparticles for drug delivery applications
    Rasouli E, Basirun WJ, Johan MR, Rezayi M, Darroudi M, Shameli K, et al.
    J Cell Biochem, 2019 04;120(4):6624-6631.
    PMID: 30368873 DOI: 10.1002/jcb.27958
    In the present research, we report a greener, faster, and low-cost synthesis of gold-coated iron oxide nanoparticles (Fe3 O4 /Au-NPs) by different ratios (1:1, 2:1, and 3:1 molar ratio) of iron oxide and gold with natural honey (0.5% w/v) under hydrothermal conditions for 20 minutes. Honey was used as the reducing and stabilizing agent, respectively. The nanoparticles were characterized by X-ray diffraction (XRD), UV-visible spectroscopy, field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDXS), transmission electron microscopy (TEM), selected area electron diffraction (SAED), vibrating sample magnetometer (VSM), and fourier transformed infrared spectroscopy (FT-IR). The XRD analysis indicated the presence of Fe3 O4 /Au-NPs, while the TEM images showed the formation of Fe3 O4 /Au-NPs with diameter range between 3.49 nm and 4.11 nm. The VSM study demonstrated that the magnetic properties were decreased in the Fe3 O4 /Au-NPs compared with the Fe3 O4 -NPs. The cytotoxicity threshold of Fe3 O4 /Au-NPs in the WEHI164 cells was determined by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. It was demonstrated no significant toxicity in higher concentration up to 140.0 ppm which can become the main candidates for biological and biomedical applications, such as drug delivery.
  17. L-Glutamine-assisted synthesis of ZnO oatmeal-like/silver composites as an electrochemical sensor for Pb2+ detection
    Mahmoudian MR, Basirun WJ, Woi PM, Yousefi R, Alias Y
    Anal Bioanal Chem, 2019 Jan;411(2):517-526.
    PMID: 30498983 DOI: 10.1007/s00216-018-1476-x
    We report a green synthesis of oatmeal ZnO/silver composites in the presence of L-glutamine as an electrochemical sensor for Pb2+ detection. The synthesis was performed via the direct reduction of Ag+ in the presence of L-glutamine in NaOH. X-ray diffraction indicated that the Ag+ was completely reduced to metallic Ag. The field emission scanning electron microscopy (FESEM) and energy dispersive X-ray results confirmed an oatmeal-like morphology of the ZnO with the presence of Ag. The FESEM images showed the effect of L-glutamine on the ZnO morphology. The EIS results confirmed a significant decrease in the charge transfer resistance of the modified glassy carbon electrode due to the presence of Ag. From the differential pulse voltammetry results, a linear working range for the concentration of Pb2+ between 5 and 6 nM with LOD of 0.078 nM (S/N = 3) was obtained. The sensitivity of the linear segment is 1.42 μA nM-1 cm-2. The presence of L-glutamine as the capping agent and stabilizer decreases the size of Ag nanoparticles and prevents the agglomeration of ZnO, respectively. Graphical abstract ᅟ.
  18. Advancements in electrochemical DNA sensor for detection of human papilloma virus - A review
    Rasouli E, Shahnavaz Z, Basirun WJ, Rezayi M, Avan A, Ghayour-Mobarhan M, et al.
    Anal Biochem, 2018 09 01;556:136-144.
    PMID: 29981317 DOI: 10.1016/j.ab.2018.07.002
    Human papillomavirus (HPV) is one of the most common sexually transmitted disease, transmitted through intimate skin contact or mucosal membrane. The HPV virus consists of a double-stranded circular DNA and the role of HPV virus in cervical cancer has been studied extensively. Thus it is critical to develop rapid identification method for early detection of the virus. A portable biosensing device could give rapid and reliable results for the identification and quantitative determination of the virus. The fabrication of electrochemical biosensors is one of the current techniques utilized to achieve this aim. In such electrochemical biosensors, a single-strand DNA is immobilized onto an electrically conducting surface and the changes in electrical parameters due to the hybridization on the electrode surface are measured. This review covers the recent developments in electrochemical DNA biosensors for the detection of HPV virus. Due to the several advantages of electrochemical DNA biosensors, their applications have witnessed an increased interest and research focus nowadays.
  19. Enhanced amperometric detection of paracetamol by immobilized cobalt ion on functionalized MWCNTs - Chitosan thin film
    Akhter S, Basirun WJ, Alias Y, Johan MR, Bagheri S, Shalauddin M, et al.
    Anal Biochem, 2018 06 15;551:29-36.
    PMID: 29753720 DOI: 10.1016/j.ab.2018.05.004
    In the present study, a nanocomposite of f-MWCNTs-chitosan-Co was prepared by the immobilization of Co(II) on f-MWCNTs-chitosan by a self-assembly method and used for the quantitative determination of paracetamol (PR). The composite was characterized by field emission scanning electron microscopy (FESEM) and energy dispersive x-ray analysis (EDX). The electroactivity of cobalt immobilized on f-MWCNTs-chitosan was assessed during the electro-oxidation of paracetamol. The prepared GCE modified f-MWCNTs/CTS-Co showed strong electrocatalytic activity towards the oxidation of PR. The electrochemical performances were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). Under favorable experimental conditions, differential pulse voltammetry showed a linear dynamic range between 0.1 and 400 μmol L-1 with a detection limit of 0.01 μmol L-1 for the PR solution. The fabricated sensor exhibited significant selectivity towards PR detection. The fabricated sensor was successfully applied for the determination of PR in commercial tablets and human serum sample.
  20. Fulltext Ultrasmall superparamagnetic Fe3O4 nanoparticles: honey-based green and facile synthesis and in vitro viability assay
    Rasouli E, Basirun WJ, Rezayi M, Shameli K, Nourmohammadi E, Khandanlou R, et al.
    Int J Nanomedicine, 2018;13:6903-6911.
    PMID: 30498350 DOI: 10.2147/IJN.S158083
    Introduction: In the present research, we report a quick and green synthesis of magnetite nanoparticles (Fe3O4-NPs) in aqueous solution using ferric and ferrous chloride, with different percentages of natural honey (0.5%, 1.0%, 3.0% and 5.0% w/v) as the precursors, stabilizer, reducing and capping agent, respectively. The effect of the stabilizer on the magnetic properties and size of Fe3O4-NPs was also studied.

    Methods: The nanoparticles were characterized by X-ray diffraction (XRD) analysis, field emission scanning electron microscopy, energy dispersive X-ray fluorescence, transmission electron microscopy (TEM), vibrating sample magnetometry (VSM) and Fourier transform infrared spectroscopy.

    Results: The XRD analysis indicated the presence of pure Fe3O4-NPs while the TEM images indicated that the Fe3O4-NPs are spherical with a diameter range between 3.21 and 2.22 nm. The VSM study demonstrated that the magnetic properties were enhanced with the decrease in the percentage of honey. In vitro viability evaluation of Fe3O4-NPs performed by using the MTT assay on the WEHI164 cells demonstrated no significant toxicity in higher concentration up to 140.0 ppm, which allows them to be used in some biological applications such as drug delivery.

    Conclusion: The presented synthesis method can be used for the controlled synthesis of Fe3O4-NPs, which could be found to be important in applications in biotechnology, biosensor and biomedicine, magnetic resonance imaging and catalysis.

Related Terms
    Try searching for something
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links