ORCID Profile
0000-0001-7366-4746
Current Organisation
Biruni University
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Publisher: Elsevier BV
Date: 2018
Publisher: Elsevier BV
Date: 2020
DOI: 10.1016/J.IJBIOMAC.2019.12.013
Abstract: Nowadays, there is increasing number of electrochemical biosensors which utilize chitosan (Ch) as an enzyme immobilization matrix, and conductive nanomaterials as electron carriers improving sensitivity of the biosensor. However, the challenge these sensors face is the lack of uniform dispersion of nanomaterials throughout the Ch film, which can negatively affect analytical performance of the biosensor. In this study, we report the development of an enzyme immobilization matrix that displays enhanced electrochemical performance thanks to a novel conductive thin film prepared via in situ electrocopolymerization of pyrrole (Py) and thiophene-grafted chitosan (Th-Ch). This is a simple thin film preparation method that can help overcome aforementioned challenges by providing a uniformly distributed conductive layer on the electrode. We are also for the first time reporting the synthesis and characterization of Th-Ch, where grafted Th plays an essential role as a linking group between Ch and Py. The resulting conductive Ch-based thin film was modified with glucose oxidase (GOx) which served as a model enzyme. In situ electrocopolymerization of Py with Th-Ch resulted in a highly conductive thin film enabling approximately 40% higher sensitivity when compared to a Py-Ch composite. This new type of composite thin film is promising in biosensor technology due to its biocompatibility, the chemically and physically modifiable structure, as well as its electrical conductivity.
Publisher: Elsevier BV
Date: 11-2015
Publisher: Elsevier BV
Date: 05-2019
Publisher: Elsevier BV
Date: 2016
DOI: 10.1016/J.MSEC.2015.09.052
Abstract: their effects on the properties of these biosensors. Biosensors were prepared by Horseradish peroxidase (HRP) immobilization on the composite electrodes composed of carbon black, carbon nanofiber (CNF), extended graphite, multiwalled carbon nanotube (MWCNT), reduced graphene oxide (REGO) and poly(glycidyl methacrylateco-vinylferrocene) (P(GMA-co-VFc)) as mediator, covalent linker, and host matrix for carbon derivatives. The modified pencil graphite electrode (PGE) was used for the detection of hydrogen peroxide and to follow electrochemical behavior of different carbon derivatives which were recorded. The electrochemical characterization was investigated by cyclic voltammetry and electrochemical impedance spectroscopy methods. Amperometric measurements showed that the REGO and MWCNT modified electrodes have excellent performance in comparison with other carbon derivatives studied.
Publisher: Elsevier BV
Date: 07-2017
Publisher: Elsevier BV
Date: 05-2017
DOI: 10.1016/J.BIOS.2017.01.030
Abstract: A comparative study is reported where folic acid (FA) and boronic acid (BA) based cytosensors and their analytical performances in cancer cell detection were analyzed by using electrochemical impedance spectroscopy (EIS) method. Cytosensors were fabricated using self-assembled monolayer principle by modifying Au electrode with cysteamine (Cys) and immobilization of ferrocene cored polyamidiamine dendrimers second generation (Fc-PAMAM (G2)), after which electrodes were modified with FA and BA. Au/Fc-PAMAM(G2)/FA and Au/Fc-PAMAM(G2)/BA based cytosensors showed extremely good analytical performances in cancer cell detection with linear range of 1×10
Publisher: Springer Science and Business Media LLC
Date: 14-10-2016
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.ENZMICTEC.2014.09.007
Abstract: In this study, a novel glucose biosensor was fabricated by reconstitutional immobilization of glucose oxidase (GOx) onto a poly(glycidyl methacrylate-co-vinylferrocene) (poly(GMA-co-VFc)) film coated pencil graphite electrode (PGE). The erometric current response of poly(GMA-co-VFc)-GOx to glucose is linear in the concentration range between 1 and 16mM (correlation coefficient of 0.9998) with a detection limit of 2.7μM (S/N=3). Experimental parameters were studied in detail and optimized, including the pH and temperature governing the analytical performance of the biosensor. The stability and reusability of the biosensor as well as its kinetic parameters have also been studied.
Publisher: Elsevier BV
Date: 04-2017
DOI: 10.1016/J.BIOS.2016.10.100
Abstract: The detection of cancer cells through important molecular recognition target such as sialic acid is significant for the clinical diagnosis and treatment. There are many electrochemical cytosensors developed for cancer cells detection but most of them have complicated fabrication processes which results in poor reproducibility and reliability. In this study, a simple, low-cost, and highly sensitive electrochemical cytosensor was designed based on boronic acid-functionalized polythiophene. In cytosensors fabrication simple single-step procedure was used which includes coating pencil graphite electrode (PGE) by means of electro-polymerization of 3-Thienyl boronic acid and Thiophen. Electrochemical impedance spectroscopy and cyclic voltammetry were used as an analytical methods to optimize and measure analytical performances of PGE/P(TBA
Publisher: Elsevier BV
Date: 09-2016
Publisher: Wiley
Date: 02-04-2013
Publisher: Elsevier BV
Date: 09-2013
Publisher: Springer Science and Business Media LLC
Date: 08-04-2019
DOI: 10.1007/S00216-019-01739-9
Abstract: We present an electrochemical DNA detection strategy based on self-assembled ferrocene-cored poly(amidoamine) dendrimers for the detection of a gene relevant to breast cancer. The chemisorption of three ferrocene-cored poly(amidoamine) generations and hybridization of single-stranded DNA on a Au electrode were studied by cyclic voltammetry and differential pulse voltammetry. The biosensor demonstrated high sensitivity of 0.13 μA/(ng/ml) in the detection of the target DNA with a linear range of 1.3-20 nM and a detection limit of 0.38 nM. The DNA biosensor also has high selectivity for the target DNA, showing a clear signal difference from a noncomplementary sequence and a single-base-mismatch sequence, which was used as a model of BRAC1 gene mutation. The results shown are highly motivating for exploring DNA biosensing technology in the diagnosis of breast cancer caused by mutation of the BRAC1 gene. Graphical abstract.
Publisher: Elsevier BV
Date: 03-2016
Publisher: American Chemical Society (ACS)
Date: 12-08-2020
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.MSEC.2016.11.127
Abstract: In this study we report a new, simple and first impedimetric biosensor based on 3-Thienyl boronic acid for dopamine detection. Biosensor electrode preparation is 1min long by simple electro-polymerization of 3-Thienyl boronic acid and copolymer Thiophene P(TBA
Publisher: American Scientific Publishers
Date: 10-2014
DOI: 10.1166/SL.2014.3338
Publisher: Springer Science and Business Media LLC
Date: 06-11-2019
DOI: 10.1007/S00604-019-3842-6
Abstract: This review (with 160 ref.) summarizes the progress that has been made in the methods for chemical or biochemical sensing of hypoxanthine and xanthine, which are produced as part of purine metabolism and are precursors of uric acid. An introduction discusses the importance of hypoxanthine and xanthine as analytes due to their significance in the clinical and food science, together with the conventional methods of analysis. A large section covers methods for the electrochemical hypoxanthine and xanthine sensing. It is ided into subsections according to the nanomaterials used including carbon nanomaterials, meal oxide nanoparticles, metal organic frameworks, conductive polymers, and bio-nanocomposites. A further large section covers optical methods for hypoxanthine and xanthine sensing, with subsections on nanomaterials including carbon nanomaterials, nanosheets, nanoclusters, nanoparticles, and their bio-nanocomposites. A concluding section summarizes the current status, addresses current challenges, and discusses future perspectives. Graphical abstractSchematic representation of the hypoxanthine and xanthine electrochemical and optical sensors incorporating various nanomaterials like graphene, carbon nanotubes (CNT), quantum dots (QD), nanoparticles and polymers, which are implemented in clinical and food analysis.
Publisher: American Chemical Society (ACS)
Date: 05-05-2020
Publisher: Elsevier BV
Date: 08-2015
DOI: 10.1016/J.FOODCHEM.2015.02.104
Abstract: A novel nanocomposite host matrix for enzyme immobilization of xanthine oxidase was developed by incorporating MWCNT in poly(GMA-co-VFc) copolymer film. In the food industry fish is a product with a very low commercial life, and a high variability as well elevated level of xanthine is an important biomarker as a sign of spoilage. The fabricated process was characterized by scanning electron microscopy (SEM), and the electrochemical behaviors of the biosensor were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The prepared enzyme electrodes exhibited maximum response at pH 7.0 and 45°C +0.35 V and reached 95% of steady-state current in about ∼ 4 s and its sensitivity was 16 mAM(-1). Linear ranges (2-28 μM, 28-46 and 46-86 μM), analytical performance and a low detection limit 0.12 μM obtained from the xanthine biosensor gives reliable results in measuring xanthine concentration in the fish meat. All the results indicating that the resulting biosensor exhibited a good response to xanthine that was related to the addition of MWCNT in the polymeric mediator film which played an important role in the biosensor performance. In addition, the biosensor exhibited high good storage stability and satisfactory anti-interference ability.
Publisher: The Journal of Food and Drug Analysis (JFDA), Food and Drug Administration, Taiwan (TFDA)
Date: 07-2017
DOI: 10.1016/J.JFDA.2016.12.005
Abstract: The aim of this study was the electrochemical detection of the adenosine-3-phosphate degradation product, xanthine, using a new xanthine biosensor based on a hybrid bio-nanocomposite platform which has been successfully employed in the evaluation of meat freshness. In the design of the erometric xanthine biosensor, chitosan-polypyrrole-gold nanoparticles fabricated by an in situ chemical synthesis method on a glassy carbon electrode surface was used to enhance electron transfer and to provide good enzyme affinity. Electrochemical studies were carried out by the modified electrode with immobilized xanthine oxidase on it, after which the biosensor was tested to ascertain the optimization parameters. The Biosensor exhibited a very good linear range of 1-200 μM, low detection limit of 0.25 μM, average response time of 8 seconds, and was not prone to significant interference from uric acid, ascorbic acid, glucose, and sodium benzoate. The resulting bio-nanocomposite xanthine biosensor was tested with fish, beef, and chicken real-s le measurements.
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.ENZMICTEC.2017.04.002
Abstract: Herein, an electrochemical urea sensing bio-electrode is reported that has been constructed by firstly electropolymerizing 4-(2,5-Di(thiophen-2-yl)-1H-pyrrol-1-yl)aniline monomer (SNS-Aniline) on Pencil Graphite Electrode (PGE), then modifying the polymer coated electrode surface with di-amino-Ferrocene (DAFc) as the mediator, and lastly Urease enzyme through glutaraldehyde crosslinking. The effect of pH, temperature, polymer thickness, and applied potential on the electrode current response was investigated besides performing storage and operational stability experiments with the interference studies. The resulting urea biosensor's erometric response was linear in the range of 0.1-8.5mM with the sensitivity of 0.54μA/mM, detection limit of 12μM, and short response time of 2s. The designed bio-electrode was tested with real human blood and urine s les where it showed excellent analytical performance with insignificant interference.
Publisher: Wiley
Date: 04-03-2021
Abstract: Current technology for blood glucose level monitoring is mainly based on the invasive finger‐prick extraction of a small drop of blood using a lancet and measured via a handheld glucometer, which is not conducive to continuous measurements. Interstitial fluid (ISF) is gaining attention as an alternative biofluid. Its biochemical composition is very similar to that of blood and it can be monitored in a continuous manner via minimally invasive methods that cause no pain and minimize any risk of infection. Herein, a microneedle array (MNA) based transdermal sensing system for the pain free monitoring of ISF glucose is presented. High‐density silicon microneedles ( ≈ 9500 microneedles cm −2 ) are used to prepare a three‐electrode patch for the electrochemical monitoring of glucose. The MNA glucose patch shows very good selectivity when tested in artificial ISF, with a sensitivity of 0.1622 µ A m m −1 cm −2 and a detection limit of 0.66 m m . In vivo application of the microneedle array in mice shows that the ISF glucose concentrations obtained with the MNA sensor gave very good correlation with the blood glucose levels determined with a commercial glucometer. This microneedle‐based sensing system hence provides an alternative transdermal diagnostic tool to the invasive existing techniques.
No related grants have been discovered for Mehmet Senel.