Chemistry / Kimya
Permanent URI for this collectionhttps://hdl.handle.net/11147/4072
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Research Project İzmir Yüksek Teknoloji Enstitüsü Ar-Ge Stratejisi Belgesi (Nanoteknoloji Araştırmaları)(2017) ; ; ; ; ; ; Özçelik, SerdarBir devlet üniversitesi olan İzmir Yüksek Teknoloji Enstitüsü (İYTE) hem de temel bilimsel hem de mühendislik gibi uygulamalı bilimsel araştırmalarda, özelleşmiş bir teknoloji üniversitesidir. 187 öğretim üyesi olan İYTE?de son on yılda gerçekleştirilen projeler ve yayınlar değerlendirildiğinde, Mayıs 2017 itibarıyla nanoteknoloji alanında çalışmış veya çalışmayı planlayan dokuz bölümde toplam 46 öğretim üyesi (%24), 203 doktora ve yüksek lisans öğrencisi (%13) bulunmaktadır. Araştırmacılara hizmet veren uzman kadrosu ile birlikte, toplam 265 araştırmacının varlığı, İYTE?yi nanoteknoloji alanında çalışmalar yapan kritik sayıda insan kaynağına (kritik kütleye) sahip olduğunu göstermektedir. Son on yıllık süreçte, BAP projeleri hariç, İYTE?de yapılan ve tamamlanan 254 projeden 75 adedi (%30), ve devam eden 75 projeden 44 adedi (%59) nanoteknoloji alanıyla ilişkilidir. Nanoteknoloji çalışmaları yapan öğretim üyeleri 2007-2016 yılları arasında 677 makale yayınlanmış (toplam yayına oranı % 29) ve bu yayınlara 17,359 atıf (toplam atıfa oranı % 56) ve makale başına 26 atıf yapılmıştır. Sadece İYTE adresli yayın sayısı 242 (% 33 ü yüksek etkili dergilede), toplam atıf sayısı 3238, makale başına atıf sayısı ise 13.5 olmuştur. İYTE nanoteknoloji grubu, enstitünün araştırmacı insan kaynağının %14?üne sahip iken, yapılan bilimsel çalışmaların %29?nı üreterek, önemli bir katma değer sağlamaktadır. 2015 yılında Türkiye?deki üniversiteler arasında öğretim üyesi başına yapılan nanoteknoloji ilişkili makale sayısında İYTE 2. sırada yer almıştır. İYTE?nin nanoteknoloji vizyonu 2023 yılında ?Türkiye?nin nanoteknoloji üssü? olmasıdır. Bu hedefe ulaşmak için, önümüzdeki beş yıllık süreç sonunda, nanoteknoloji alanında çalışan öğretim üyesi sayısı en az 60 (%25 artış), lisans üstü öğrenci sayısı ise en az 360 (%80 artış) olmalıdır. İYTE adresli nano-ilişkili yayın sayısı 2023 yılında 150 (%50 si yüksek etkili dergilerde olmak üzere) olacak şekilde bir hedef belirlenmiştir. Bu çalışmaları desteklemek amacıyla, cihaz altyapısının yenilenmesi ve bazı önemli ama pahalı cihazların satın alınabilmesi için önümüzdeki beş yıllık sürede İYTE?nin 12.0 milyon euro mertebesinde bir dış finansmana ihtiyacı bulunmaktadır.Article Citation - WoS: 4Citation - Scopus: 5Development of Ab3-Type Novel Phthalocyanine and Porphyrin Photosensitizers Conjugated With Triphenylphosphonium for Higher Photodynamic Efficacy(American Chemical Society, 2022) Albakour, Mohamad; Önal, Emel; Tüncel, Özge; Erdoğan, İpek; Gümüşgöz Çelik, Gizem; Küçük, Tuǧba; Akgül, Bünyamin; Gürek, Ayşe Gül; Özçelik, SerdarThere are a number of lipophilic cations that can be chosen; the triphenylphosphonium (TPP) ion is particularly unique for mitochondrion targeting, mainly due to its simplicity in structure and ease to be linked to the target molecules. In this work, mitochondrion-targeted AB3-type novel phthalocyanine and porphyrin photosensitizers (PSs) were synthesized and their photophysical photochemical properties were defined. Fluorescence quantum yields (φF) are 0.009, 0.14, 0.13, and 0.13, and the singlet-oxygen quantum yields (φΔ) are 0.27, 0.75, 0.57, and 0.58 for LuPcPox(OAc), AB3TPP-Pc, AB3TPP-Por-C4, and AB3TPP-Por-C6, respectively. To evaluate the photodynamic efficacy of the TPP-conjugated PS cell viabilities of A549 and BEAS-2B lung cells were comparatively measured and IC-50 values were determined. AB3TPP-Por-C4, AB3TPP-Por-C6, and AB3TPP-Pc compounds compared to the reference molecules ZnPc and H2TPP were found to be highly cytotoxic (sub-micromolar concentration) under the light. LuPcPox(OAc) is the most effective molecule regarding cell killing (the activity). The cell killing of the TPP-conjugated porphyrin derivatives exhibits a similar response compared to LuPcPox(OAc) when the light absorbing factor of the PS is normalized at 660 nm: TPP-conjugated porphyrins absorb less light (lower extinction coefficient) but produce more radical species (higher singlet-oxygen quantum yield) and therefore effectively kill the cells. The singlet oxygen-producing capacity of AB3TPP-Pc is almost 3 times higher compared to LuPcPox(OAc) and 50% more efficient with respect to ZnPc, suggesting that TPP-conjugated phthalocyanine may serve as a good photosensitizer for photodynamic therapy (PDT). The high singlet oxygen generation capacity of these novel TPP-conjugated porphyrin and phthalocyanine PS suggests that they might be useful for PDT requiring lower photosensitizer concentration and reduced energy deposited through less light exposure.Article Citation - WoS: 7Citation - Scopus: 10Enhanced Light–matter Interaction in a Hybrid Photonic–plasmonic Cavity(Springer, 2021) Gökbulut, Belkıs; İnanç, Arda; Topçu, Gökhan; Özçelik, Serdar; Demir, Mustafa Muammer; İnci, Mehmet NaciStrongly concentrated optical fields around a metal nanoparticle in the close vicinity of a dipole noticeably facilitate dramatic changes in the localized density of states due to hybrid photonic–plasmonic mode couplings as compared to that of the pure cavity mode fields. Significant variations of the field intensity in the presence of the metal nanoparticle elucidate enhanced light–matter interaction in a hybrid structure. The enhancement factor of the light–matter interaction is studied through the single-atom cooperativity parameter, which is directly proportional to the ratio of the fluorescence lifetimes of the off-resonant and on-resonant emission. A compact and cost-effective hybrid device, which includes a microfiber cavity, supporting whispering gallery modes, and a well-defined solid nanostructure, consisting of a gold nanoparticle core, overcoated by a silica shell, and decorated with CdS/CdSe quantum dots, is demonstrated to offer an outstanding potential for the enhancement of light–matter interaction. Surface plasmons of a gold nanoparticle, placed inside a hollow cylindrical nanostructure at the surface of a microfiber, are activated upon excitation of the dipoles of the quantum emitters, which are on-resonance with the whispering gallery mode. Time-resolved experiments demonstrate that the single-atom cooperativity parameter of the quantum dots is enhanced by a factor of about 4.8 in the presence of the gold nanoparticle being simultaneously in strong interaction with the cavity mode field and the metal nanoparticle’s surface plasmons.Correction Correction To: Enhanced Light–matter Interaction in a Hybrid Photonic–plasmonic Cavity(Springer, 2022) Gökbulut, Belkıs; İnanç, Arda; Topçu, Gökhan; Özçelik, Serdar; Demir, Mustafa Muammer; İnci, Mehmet NaciIn this article the statement in the Funding information section was incorrect. The correct Funding information is as follows. ‘Dr Belkıs Gökbulut acknowledges TUBITAK for the financial support provided under Contract Number 120F323’.Article Citation - WoS: 3Citation - Scopus: 6Hybrid Photonic-Plasmonic Mode-Coupling Induced Enhancement of the Spontaneous Emission Rate of Cds/Cdse Quantum Emitters(Elsevier, 2022) Gökbulut, Belkıs; İnanç, Arda; Topçu, Gökhan; Özçelik, Serdar; Demir, Mustafa Muammern this paper, a hybrid photonic-plasmonic resonator, which comprises an electrospun polymer fiber with a micrometer diameter and a core/shell nanostructure with a gold nanoparticle core, is constructed to investigate the dynamics of the coupled spontaneous emission of CdS/CdSe quantum dots (QDs). The gold nanoparticle core; covered with a silica shell, anchored with individual CdS/CdSe QDs, is placed inside a hollow cylindrical nanocavity formed on the surface of the microfiber to enable integration of the optical mode with the plasmonic effect, which is induced by the localized surface plasmons of the metal nanoparticle being present in the vicinity of the dipoles. The spontaneous emission rate of the QDs, coupled into the hybrid photonic-plasmonic mode, is measured to enhance by a factor of 23 via a time-resolved experimental technique. This result suggests that the regeneration of the optical mode-field inside the photonic-plasmonic resonator through the interaction of the dipoles with the localized surface plasmons of a metal nanoparticle strongly enhances the density of the electromagnetic states of the quantum emitters to facilitate an enhanced spontaneous emission within the host medium of the proposed polymer based-photonic structure.Article Citation - WoS: 13Citation - Scopus: 14Synthesizing and Evaluating the Photodynamic Efficacy of Asymmetric Heteroleptic A(7)b Type Novel Lanthanide Bis-Phthalocyanine Complexes(Royal Society of Chemistry, 2021) Önal, Emel; Tüncel, Özge; Albakour, Mohamad; Gümüşgöz Çelik, Gizem; Gül Gürek, Ayşe; Özçelik, SerdarIn this study heteroleptic A(7)B type novel Lu(iii) and Eu(iii) lanthanide phthalocyanines (LnPc(Pox)[Pc '(AB(3)SH)]) with high extinction coefficients have been synthesized as candidate photosensitizers with reaction yields higher than 33%. The singlet oxygen quantum yields of LuPc(Pox)[Pc '(AB(3)SH)] and EuPc(Pox)[Pc '(AB(3)SH)], respectively, were measured 17% and 1.4% by the direct method in THF. The singlet oxygen quantum yield of LuPc(Pox)[Pc '(AB(3)SH)] in THF is the highest among lutetium(iii) bis-phthalocyanine complexes to date. The photodynamic efficacy of the heteroleptic lanthanide phthalocyanines was evaluated by measuring cell viabilities of A549 and BEAS-2B lung cells, selected to representing in vitro models for testing cancer and normal cells against potential drugs. The cell viabilities demonstrated concentration dependent behavior and were varied by the type of phthalocyanines complexes. Irradiation of the cells for 30 minutes with LED array at 660 nm producing flux of 0.036 J cm(-2) s(-1) increased cell death for LuPcPox-OAc, LuPc(Pox)[Pc '(AB(3)SH)] and ZnPc. The IC50 concentrations of LuPc(Pox)[Pc '(AB(3)SH)] and ZnPc were determined to be below 10 nM for both cell lines, agreeing very well with the singlet oxygen quantum yield measurements. These findings suggest that LuPc(Pox)[Pc '(AB(3)SH)] and particularly LuPcPox-OAc are promising drug candidates enabling lowered dose and shorter irradiation time for photodynamic therapy.Article Citation - WoS: 2Citation - Scopus: 31-Octanol Is a Functional Impurity Modifying Particle Size and Photophysical Properties of Colloidal Zncdsse/Zns Nanocrystals(American Chemical Society, 2021) Sevim Ünlütürk, Seçil; Çağır, Ali; Varlıklı, Canan; Özçelik, SerdarImpurities in trioctylphophine (TOP) strongly affect nanocrystal synthesis. 1-Octanol among other contaminants in TOP is identified for the first time as a functional impurity by H-1 NMR. The deliberate addition of 1-octanol into trioctylphosphine reduced particle size and modified photophysical properties of ZnCdSSe/ZnS colloidal nanocrystals. NMR analysis furthermore revealed that 1-octanol is bonded to the nanocrystal surfaces. The ratio of integrals for the O-CH2 protons of 1-octanol, which is the lowest compared to the other ligands, suggests that 1-octanol plays a critical role to tune the particle size of nanocrystals. The increased amount of 1-octanol added into TOP reduces the particle size from 9.8 to 7.2 nm, causing a progressive blue shift in the UV-vis and PL spectra but leaving the alloy composition unaffected. The rate of nonradiative processes is enhanced with the amount of 1-octanol added into TOP, correlating with higher dislocation density observed in the nanocrystals. As a conclusion, 1-octanol is proposed as a functional impurity that varies particle size and nonradiative photophysical processes in the ZnCdSSe/ZnS colloidal nanocrystals.Article Citation - WoS: 4Citation - Scopus: 6An Anticounterfeiting Technology Combining an Inp Nanoparticle Ink and a Versatile Optical Device for Authentication(Royal Society of Chemistry, 2021) Taşcıoğlu, Didem; Sevim Ünlütürk, Seçil; Özçelik, SerdarCounterfeiting is a growing issue and causes economic losses. Fluorescent inks containing In(Zn)P/ZnS/DDT colloidal nanoparticles are formulated and combined with a convenient optical device for authentication. The particle size and fluorescent colors of the colloidal nanoparticles were tuned by adjusting the reaction temperature. The particle stability and brightness were improved by the addition of dodecanethiol, coating the particle surface with an organic shell. Security patterns were printed on various substrates by applying the screen-printing technique. The patterns were invisible under daylight but observable under UV-light illumination, displaying five different emission colors. By adjusting the concentration of the nanoparticles in the ink, the security patterns were made almost not observable under UV-light illumination but clearly identified by a commercial fiber optics-based spectrometer and a handheld optical device, called a Quantag sensor that was developed in-house. Furthermore, the spectral signatures of barely noticeable patterns are unambiguously validated by the Quantag sensor. Accordingly, low cost and easily applicable anticounterfeiting technology powered by custom-formulated fluorescent inks and a handheld optical instrument are developed to authenticate valuable documents and products.Article Citation - WoS: 22Citation - Scopus: 18Nuclear-Targeted Gold Nanoparticles Enhance Cancer Cell Radiosensitization(IOP Publishing, 2020) Pratx, Guillem; Özçelik, SerdarRadiation therapy aims to kill or inhibit proliferation of cancer cells while sparing normal cells. To enhance radiosensitization, we developed 40 nm-sized gold nanoparticles targeting the nucleus. We exploited a strategy that combined RGD and NLS peptides respectively targeting cancer cell and the nucleus to initiate cell-death activated by x-ray irradiation. We observed that the modified gold nanoparticles were either translocated in the nuclei or accumulated in the vicinity of the nuclei. We demonstrated that x-ray irradiation at 225 kVp energy reduced cell proliferation by 3.8-fold when the nuclear targeted gold nanoparticles were used. We determined that the radiation dose to have a 10% survival fraction was reduced from 11.0 Gy to 7.1 Gy when 10.0 mu g ml(-1)of the NLS/RGD/PEG-AuNP was incubated with A549 cancer cells. We conclude that the peptide-modified gold nanoparticles targeting the nucleus significantly enhance radiosensitization.Article Citation - WoS: 8Citation - Scopus: 7Engineered Silica Nanoparticles Are Biologically Safe Vehicles To Deliver Drugs or Genes To Liver Cells(Elsevier Ltd., 2021) Tüncel, Özge; Kahraman, Erkan; Bağcı, Gülsün; Atabey, Neşe; Özçelik, SerdarEngineered silica nanoparticles (SiNP) are emerging materials for medical applications. Evaluating biological responses of specific cells treated with engineered silica nanoparticles is however essential. We synthesized and characterized the physicochemical properties of silica nanoparticles with two different sizes of 10 and 100 nm (10SiNP and 100SiNP) dispersed in cell culture medium. HuH-7, an epithelial-like human hepatoblastoma cell line and SK-HEP-1, a liver sinusoidal endothelial cell line (LSEC) are employed to evaluate their biological responses for the SiNP treatment. Primary human lymphocytes are used to assess genotoxicity recommended by OECD guidelines while erythrocytes are used to assess hemolytic activity. The engineered silica nanoparticles are not able to produce radical species, to alter the mitochondrial membrane potential, and induce any adverse effects on cell proliferation. The colony formation ability of HuH-7 hepatoblastoma cells was not affected following the SiNP treatment. Furthermore, SiNPs do not induce hemolysis of red blood cells and are not genotoxic. These findings suggest that SiNPs regardless of the size, amount, and incubation time are biologically safe vehicles to deliver drugs or genes to the liver. © 2020 Elsevier B.V.