Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Subject: search.filters.subject.Gold nanoparticlesWoS Q: search.filters.wosQuartile.Q1

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  • Article
    Citation - WoS: 7
    Citation - Scopus: 9
    A Screen-Printed Electrode Modified With Gold Nanoparticles/ Cellulose Nanocrystals for Electrochemical Detection of 4,4'-methylene Diphenyl Diamine
    (Elsevier, 2023) Büyüktaş, Duygu; Ghaani, Masoud; Rovera, Cesare; Carullo, Daniele; Olsson, Richard T.; Korel, Figen; Farris, Stefano
    Developing simple, cost-effective, easy-to-use, and reliable analytical devices if of utmost importance for the food industry for rapid in-line checks of their products that must comply with the provisions set by the current legislation. The purpose of this study was to develop a new electrochemical sensor for the food packaging sector. More specifically, we propose a screen -printed electrode (SPE) modified with cellulose nanocrystals (CNCs) and gold nanoparticles (AuNPs) for the quantification of 4,4'-methylene diphenyl diamine (MDA), which is one of the most important PAAs that can transfer from food packaging materials into food stuffs. The electrochemical performance of the proposed sensor (AuNPs/CNCs/SPE) in the presence of 4,4'- MDA was evaluated using cyclic voltammetry (CV). The modified AuNPs/CNCs/SPE showed the highest sensitivity for 4,4'-MDA detection, with a peak current of 9.81 mu A compared with 7.08 mu A for the bare SPE. The highest sensitivity for 4,4'-MDA oxidation was observed at pH = 7, whereas the detection limit was found at 57 nM and the current response of 4,4'-MDA rose linearly as its concentration increased from 0.12 mu M to 100 mu M. Experiments using real packaging materials revealed that employing nanoparticles dramatically improved both the sensitivity and the selectivity of the sensor, which can be thus considered as a new analytical tool for quick, simple, and accurate measurement of 4,4 '-MDA during converting operations.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 5
    Effect of Chain Topology on Plasmonic Properties of Pressure Sensor Films Based on Poly(acrylamide) and Au Nanoparticles
    (Elsevier Ltd., 2019) Topçu, Gökhan; Demir, Mustafa Muammer
    Au nanoparticles have been recognized as a colorimetric sensing element in polymeric systems because clustering shifts the red color of individual particles into saturated blue due to distinct plasmonic variation. The mechanism of pressure sensing is based on the disintegration of the particle clusters into the individual particles in polymers upon application of pressure. Polymers are usually composed of linear chains that provide a viscoelastic medium for their diffusion. Changing topology of polymer chains from linear to crosslinked under fixed pressure makes a clear change in spectral features of the particles probably due to the hindrance of particle diffusion by the crosslinking points. Therefore, the working range of the sensor films can be increased to higher-pressure values. In this work, polyacrylamide/Au nanoparticle films were prepared by various concentrations of formaldehyde as a crosslinking agent from 0.5 to 5.0 wt %. The initial absorption signal gradually shifts from 690 to 545 nm for linear chains upon application of pressure while shifting goes down to 571 nm for crosslinked ones. The colorimetric change is also examined under humid environments. Contrary to the crosslinking process, humid environment facilitates the diffusion of particles since the chains swell with water molecules that provide a convenient medium for particle diffusion.