1. Crystallizing covalent organic frameworks from metal organic framework through chemical induced‑phase engineeringAbdul Khayum Mohammed, Safa Gaber, Jesus Raya, Tina Skorjanc, Nada Elmerhi, Sasi Stephen, Pilar Pena Sanchez, Felipe Gandara, Steven J. Hinder, Mark A. Baker, Kyriaki Polychronopoulou, Dinesh Shetty, 2023, izvirni znanstveni članek Opis: The ordered porous frameworks like MOFs and COFs are generally constructed using the monomers through distinctive metal-coordinated and covalent linkages. Meanwhile, the inter-structural transition between each class of these porous materials is an under-explored research area. However, such altered frameworks are expected to have exciting features compared to their pristine versions. Herein, we have demonstrated a chemical-induction phase-engineering strategy to transform a two dimensional conjugated Cu-based SA-MOF (Cu-Tp) into 2D-COFs (Cu-TpCOFs). The structural phase transition offered in-situ pore size engineering from 1.1 nm to 1.5–2.0 nm. Moreover, the Cu-TpCOFs showed uniform and low percentage-doped (~ 1–1.5%) metal distribution and improved crystallinity, porosity, and stability compared to the parent Cu-Tp MOF. The construction of a framework from another framework with new linkages opens interesting opportunities for phase-engineering.
Ključne besede: Metal organic framework, covalent organic framework, phase engineering, chemical transformation, porous materials
Objavljeno v RUNG: 10.11.2023; Ogledov: 223; Prenosov: 3
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2. In vitro tumor hypoxia imaging with fluorescent covalent organic frameworksTina Skorjanc, Dinesh Shetty, Damjan Makuc, Gregor Mali, Martina Bergant Marušič, Matjaz Valant, 2023, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Hypoxia refers to a condition where cells and tissues experience low, inadequate levels of O2. While healthy tissues are typically supplied with sufficient O2 (normoxia), cancerous tissues commonly face hypoxia due to the tumor’s extraordinarily high demand for oxygen. Various fluorescent small-molecule probes have been designed for selective detection of hypoxia in living cells, but few nanomaterials have been investigated for this type of bioimaging. Herein, we prepare a fluorescent covalent organic framework (COF) with β-ketoenamine linkages and post-synthetically modify it to conjugate hypoxia-sensitive nitroimidazole moieties
into its pores (NI-COF). Stacks of sheets in NI-COF observed under electron microscopy were exfoliated by ultrasonication, and dynamic light scattering measurements confirmed particle size of less than 200 nm. Thus-prepared material exhibited good stability in physiological conditions and low cytotoxicity in in vitro experiments. NI-COF also showed useful fluorescence properties with an emission peak at 490 nm (λex = 420 nm) at both neutral and mildly acidic pH levels that are characteristic of tumor tissues. Encouraged by the favorable properties of the material, we incubated HeLa cells pre-treated in either hypoxic or normoxic conditions with NI-COF. Fluorescence microscopy images demonstrated that the material was preferentially taken up by hypoxic cells, which showed higher fluorescence signal in their interior than cells cultured under normoxia conditions. It is anticipated that this study will stimulate further developments of COFs for imaging various biological conditions.
Ključne besede: hypoxia, fluorescence, covalent organic frameworks, imaging, tumor cells
Objavljeno v RUNG: 19.09.2023; Ogledov: 334; Prenosov: 3
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3. A Rational Design of Isoindigo-Based Conjugated Microporous n-Type Semiconductors for High Electron Mobility and ConductivityKayaramkodath Chandran Ranjeesh, Ayman Rezk, Jose Ignacio Martinez, Safa Gaber, Areej Merhi, Tina Skorjanc, Matjaz Finsgar, Gisha Elizabeth Luckachan, Ali Trabolsi, Bilal R. Kaafarani, Ammar Nayfeh, Dinesh Shetty, 2023, izvirni znanstveni članek Opis: The development of n-type organic semiconductors has evolved significantly slower in comparison to that of p-type organic semiconductors mainly due to the lack of electron-deficient building blocks with stability and processability. However, to realize a variety of organic optoelectronic devices, high-performance n-type polymer semiconductors are essential. Herein, conjugated microporous polymers (CMPs) comprising isoindigo acceptor units linked to benzene or pyrene donor units (BI and PI) showing n-type semiconducting behavior are reported. In addition, considering the challenges of deposition of a continuous and homogeneous thin film of CMPs for accurate Hall measurements, a plasma-assisted fabrication technique is developed to yield uniform thin films. The fully conjugated 2D networks in PI- and BI-CMP films display high electron mobility of 6.6 and 3.5 cm2 V−1 s−1, respectively. The higher carrier concentration in PI results in high conductivity (5.3 mS cm−1). Both experimental and computational studies are adequately combined to investigate structure–property relations for this intriguing class of materials in the context of organic electronics.
Ključne besede: conjugated microporous polymers, isoindigo, semiconductors, conductivity, electron mobility
Objavljeno v RUNG: 18.08.2023; Ogledov: 368; Prenosov: 2
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4. Enzyme-immobilized Hierarchically Porous Covalent Organic Framework Biocomposite for Catalytic Degradation of Broad-range Emerging Pollutants in WaterNada Elmerhi, Khadega Al-Maqdi, Khawlah Athamneh, Abdul Khayum Mohammed, Tina Skorjanc, Felipe Gandara, Jesus Raya, Simon Pascal, Olivier Siri, Ali Trabolsi, Iltaf Shah, Dinesh Shetty, Syed Salman Ashraf, 2023, izvirni znanstveni članek Opis: Efficient enzyme immobilization is crucial for the successful commercialization of large-scale enzymatic water treatment.
However, issues such as lack of high enzyme loading coupled with enzyme leaching present challenges for the widespread adoption
of immobilized enzyme systems. The present study describes the development and bioremediation application of an enzyme
biocomposite employing a cationic macrocycle-based covalent organic framework (COF) with hierarchical porosity for the
immobilization of horseradish peroxidase (HRP). The intrinsic hierarchical porous features of the azacalix[4]arene-based COF
(ACA-COF) allowed for a maximum HRP loading capacity of 0.76 mg/mg COF with low enzyme leaching (<5.0%). The
biocomposite, HRP@ACA-COF, exhibited exceptional thermal stability (~200% higher relative activity than the free enzyme),
and maintained ~60% enzyme activity after five cycles. LCMSMS analyses confirmed that the HRP@ACA-COF system was able
to achieve >99% degradation of seven diverse types of emerging pollutants (2-mercaptobenzothiazole, paracetamol, caffeic acid,
methylparaben, furosemide, sulfamethoxazole, and salicylic acid)in under an hour. The described enzyme-COF system offers
promise for efficient wastewater bioremediation applications.
Ključne besede: covalent organic frameworks, enzymes, emerging pollutants, water purification, biocomposite
Objavljeno v RUNG: 11.08.2023; Ogledov: 417; Prenosov: 2
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5. Covalent organic frameworks for fluorescent imaging of hypoxiaTina Skorjanc, Dinesh Shetty, Gregor Mali, Damjan Makuc, Martina Bergan Marušič, Matjaz Valant, 2023, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: hypoxia, covalent organic frameworks, imaging, fluorescence, post-synthetic modification
Objavljeno v RUNG: 06.06.2023; Ogledov: 637; Prenosov: 0
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6. Nitroreductase-sensitive fluorescent covalent organic framework for tumor hypoxia imaging in cellsTina Skorjanc, Dinesh Shetty, Sushil Kumar, Damjan Makuc, Gregor Mali, Janez Vovavšek, Martina Bergant Marušič, Matjaz Valant, 2023, izvirni znanstveni članek Ključne besede: covalent organic frameworks, imaging, hypoxia, fluorescence, cancer cells
Objavljeno v RUNG: 17.05.2023; Ogledov: 642; Prenosov: 6
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7. Salicylaldehydate coordinated two-dimensional-conjugated metal–organic frameworksAbdul Khayum Mohammed, Pilar Pena-Sanchez, Ajmal Pandikassala, Safa Gaber, Ayesha A. AlKhoori, Tina Skorjanc, Kyriaki Polychronopoulou, Sreekumar Kurungot, Felipe Gandara, Dinesh Shetty, 2023, izvirni znanstveni članek Ključne besede: metal-organic framework, 2D materials, salicylaldehyde, thin films, mechanochemistry
Objavljeno v RUNG: 10.02.2023; Ogledov: 713; Prenosov: 0
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8. Covalent Organic Framework Based on Azacalix[4]arene for the Efficient Capture of Dialysis Waste ProductsTina Škorjanc, Dinesh Shetty, Felipe Gándara, Pascal Simon, Nawavi Naleem, Salma Abubakar, Liaqat Ali, Abdul Khayum Mohammed, Jesus Raya, Serdal Kirmizialtin, 2022, izvirni znanstveni članek Ključne besede: azacalixarene, covalent organic frameworks, dialysis, uric acid, creatinine, adsorption
Objavljeno v RUNG: 08.09.2022; Ogledov: 1031; Prenosov: 0
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9. Polythiacalixarene-embedded gold nanoparticles for visible-light-driven photocatalytic CO [sub] 2 reductionTina Škorjanc, Kamal Khaja Mohaideen, Ayesha Alkhoori, Gregor Mali, Abdul Khayum Mohammed, Zouhair Asfari, Kyriaki Polychronopoulou, Blaž Likozar, Ali Trabolsi, Dinesh Shetty, 2022, izvirni znanstveni članek Ključne besede: Gold, Materials, Metal nanoparticles, Photocatalysis, Polymers
Objavljeno v RUNG: 13.07.2022; Ogledov: 1048; Prenosov: 0
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10. Covalent Organic Polymers and Frameworks for Fluorescence-Based SensorsTina Škorjanc, Dinesh Shetty, Matjaž Valant, 2021, pregledni znanstveni članek Ključne besede: fluorescence, sensors, covalent organic polymers, covalent organic frameworks, quenching, ions, explosives
Objavljeno v RUNG: 05.05.2021; Ogledov: 1863; Prenosov: 216
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