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Fried M, Bogar R, Takacs D, Labadi Z, Horvath ZE, Zolnai Z. Investigation of Combinatorial WO3-MoO3 Mixed Layers by Spectroscopic Ellipsometry using Different Optical Models. Nanomaterials 2022; 12:nano12142421. [PMID: 35889645 PMCID: PMC9317069 DOI: 10.3390/nano12142421] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 12/10/2022]
Abstract
Reactive (Ar-O2 plasma) magnetron sputtered WO3-MoO3 (nanometer scaled) mixed layers were investigated and mapped by Spectroscopic Ellipsometry (SE). The W- and Mo-targets were placed separately, and 30 × 30 cm glass substrates were slowly moved under the two (W and Mo) separated targets. We used different (oscillator- and Effective Medium Approximation, EMA-based) optical models to obtain the thickness and composition maps of the sample layer relatively quickly and in a cost-effective and contactless way. In addition, we used Rutherford Backscattering Spectrometry to check the SE results. Herein, we compare the “goodness” of different optical models depending upon the sample preparation conditions, for instance, the speed and cycle number of the substrate motion. Finally, we can choose between appropriate optical models (2-Tauc-Lorentz oscillator model vs. the Bruggeman Effective Medium Approximation, BEMA) depending on the process parameters. If one has more than one “molecular layer” in the “sublayers”, BEMA can be used. If one has an atomic mixture, the multiple oscillator model is better (more precise) for this type of layer structure.
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Affiliation(s)
- Miklos Fried
- Institute of Microelectronics and Technology, Kando Kalman Faculty of Electrical Engineering, Óbuda University, H-1084 Budapest, Hungary; (R.B.); (D.T.)
- Institute of Technical Physics and Materials Science (MFA), Centre for Energy Research, Hungarian Academy of Sciences, H-1525 Budapest, Hungary; (Z.L.); (Z.E.H.); (Z.Z.)
- Correspondence:
| | - Renato Bogar
- Institute of Microelectronics and Technology, Kando Kalman Faculty of Electrical Engineering, Óbuda University, H-1084 Budapest, Hungary; (R.B.); (D.T.)
| | - Daniel Takacs
- Institute of Microelectronics and Technology, Kando Kalman Faculty of Electrical Engineering, Óbuda University, H-1084 Budapest, Hungary; (R.B.); (D.T.)
| | - Zoltan Labadi
- Institute of Technical Physics and Materials Science (MFA), Centre for Energy Research, Hungarian Academy of Sciences, H-1525 Budapest, Hungary; (Z.L.); (Z.E.H.); (Z.Z.)
| | - Zsolt Endre Horvath
- Institute of Technical Physics and Materials Science (MFA), Centre for Energy Research, Hungarian Academy of Sciences, H-1525 Budapest, Hungary; (Z.L.); (Z.E.H.); (Z.Z.)
| | - Zsolt Zolnai
- Institute of Technical Physics and Materials Science (MFA), Centre for Energy Research, Hungarian Academy of Sciences, H-1525 Budapest, Hungary; (Z.L.); (Z.E.H.); (Z.Z.)
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Labadi Z, Kalas B, Saftics A, Illes L, Jankovics H, Bereczk-Tompa É, Sebestyén A, Tóth É, Kakasi B, Moldovan C, Firtat B, Gartner M, Gheorghe M, Vonderviszt F, Fried M, Petrik P. Sensing Layer for Ni Detection in Water Created by Immobilization of Bioengineered Flagellar Nanotubes on Gold Surfaces. ACS Biomater Sci Eng 2020; 6:3811-3820. [PMID: 33463317 DOI: 10.1021/acsbiomaterials.0c00280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The environmental monitoring of Ni is targeted at a threshold limit value of 0.34 μM, as set by the World Health Organization. This sensitivity target can usually only be met by time-consuming and expensive laboratory measurements. There is a need for inexpensive, field-applicable methods, even if they are only used for signaling the necessity of a more accurate laboratory investigation. In this work, bioengineered, protein-based sensing layers were developed for Ni detection in water. Two bacterial Ni-binding flagellin variants were fabricated using genetic engineering, and their applicability as Ni-sensitive biochip coatings was tested. Nanotubes of mutant flagellins were built by in vitro polymerization. A large surface density of the nanotubes on the sensor surface was achieved by covalent immobilization chemistry based on a dithiobis(succimidyl propionate) cross-linking method. The formation and density of the sensing layer was monitored and verified by spectroscopic ellipsometry and atomic force microscopy. Cyclic voltammetry (CV) measurements revealed a Ni sensitivity below 1 μM. It was also shown that, even after two months of storage, the used sensors can be regenerated and reused by rinsing in a 10 mM solution of ethylenediaminetetraacetic acid at room temperature.
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Affiliation(s)
- Zoltan Labadi
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest 1121, Hungary
| | - Benjamin Kalas
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest 1121, Hungary
| | - Andras Saftics
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest 1121, Hungary
| | - Levente Illes
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest 1121, Hungary
| | - Hajnalka Jankovics
- Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém 8200, Hungary
| | - Éva Bereczk-Tompa
- Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém 8200, Hungary
| | - Anett Sebestyén
- Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém 8200, Hungary
| | - Éva Tóth
- Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém 8200, Hungary
| | - Balázs Kakasi
- Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém 8200, Hungary
| | - Carmen Moldovan
- National Institute for Research & Development in Microtechnologies, Bucharest 077190, Romania
| | - Bogdan Firtat
- National Institute for Research & Development in Microtechnologies, Bucharest 077190, Romania
| | - Mariuca Gartner
- "Ilie Murgulescu" Institute of Physical Chemistry of the Romanian Academy, Bucharest 060021, Romania
| | | | - Ferenc Vonderviszt
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest 1121, Hungary.,Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém 8200, Hungary
| | - Miklos Fried
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest 1121, Hungary.,Institute of Microelectronics and Technology, Óbuda University, Budapest 1034, Hungary
| | - Peter Petrik
- Institute of Technical Physics and Materials Science, Centre for Energy Research, Budapest 1121, Hungary
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