1
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Lim J, Kim H, Park J, Moon GH, Vequizo JJM, Yamakata A, Lee J, Choi W. How g-C 3N 4 Works and Is Different from TiO 2 as an Environmental Photocatalyst: Mechanistic View. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:497-506. [PMID: 31793772 DOI: 10.1021/acs.est.9b05044] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Graphitic carbon nitride (CN) as a popular visible light photocatalyst needs to be better understood for environmental applications. The behaviors of CN as an environmental photocatalyst were systematically studied in comparison with a well-known TiO2 photocatalyst. The two photocatalysts exhibit different photocatalytic oxidation (PCO) behaviors and dependences on the experimental conditions (e.g., pH, Pt loading, and the kind of organic substrate and scavenger). The PCO of organic substrates was significantly enhanced by loading Pt on TiO2 under UV light (λ > 320 nm), whereas Pt-CN exhibited a lower PCO activity than bare CN under visible light (λ > 420 nm). While the presence of Pt enhances the charge separation in both TiO2/UV and CN/visible light systems (confirmed by transient IR absorption spectroscopic analysis), the opposite effects of Pt are ascribed to the different mechanisms of •OH generation in the two photocatalytic systems. The negative effect of Pt on CN is ascribed to the fact that Pt catalytically decomposes in situ-generated H2O2 (a main precursor of OH radical), which hinders •OH production. The production of OH radicals on CN is favored only at acidic pH but 1O2 generation is dominant in alkaline pH. The pH-dependent behaviors of reactive oxygen species generation on CN were confirmed by electron paramagnetic resonance spin trap measurements.
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Affiliation(s)
- Jonghun Lim
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Hyejin Kim
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Jihee Park
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Gun-Hee Moon
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
| | - Junie Jhon M Vequizo
- Graduate School of Engineering, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511, Japan
| | - Akira Yamakata
- Graduate School of Engineering, Toyota Technological Institute, 2-12-1 Hisakata, Tempaku, Nagoya 468-8511, Japan
| | - Jinwoo Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Wonyong Choi
- Division of Environmental Science and Engineering and Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Korea
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2
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Huang H, Tian Y. A ratiometric fluorescent probe for bioimaging and biosensing of HBrO in mitochondria upon oxidative stress. Chem Commun (Camb) 2018; 54:12198-12201. [PMID: 30306159 DOI: 10.1039/c8cc07125j] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A novel ratiometric fluorescent probe with high selectivity and sensitivity was designed and developed for bioimaging and biosensing of HBrO in mitochondria. Using this useful tool with low cytotoxicity and good biocompatibility, it was found that O2˙--induced oxidative stress triggered the burst of HBrO in mitochondria.
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Affiliation(s)
- Hong Huang
- Department of Chemistry, School of Chemistry and Molecular Engineering, East China Normal University, Dongchuan Road 500, Shanghai 200241, P. R. China.
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3
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Leong KH, Aziz AA, Sim LC, Saravanan P, Jang M, Bahnemann D. Mechanistic insights into plasmonic photocatalysts in utilizing visible light. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2018; 9:628-648. [PMID: 29527438 PMCID: PMC5827636 DOI: 10.3762/bjnano.9.59] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/17/2018] [Indexed: 05/08/2023]
Abstract
The utilisation of sunlight as an abundant and renewable resource has motivated the development of sustainable photocatalysts that can collectively harvest visible light. However, the bottleneck in utilising the low energy photons has led to the discovery of plasmonic photocatalysts. The presence of noble metal on the plasmonic photocatalyst enables the harvesting of visible light through the unique characteristic features of the noble metal nanomaterials. Moreover, the formation of interfaces between noble metal particles and semiconductor materials further results in the formation of a Schottky junction. Thereby, the plasmonic characteristics have opened up a new direction in promoting an alternative path that can be of value to the society through sustainable development derived through energy available for all for diverse applications. We have comprehensively prepared this review to specifically focus on fundamental insights into plasmonic photocatalysts, various synthesis routes, together with their strengths and weaknesses, and the interaction of the plasmonic photocatalyst with pollutants as well as the role of active radical generation and identification. The review ends with a pinnacle insight into future perspectives regarding realistic applications of plasmonic photocatalysts.
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Affiliation(s)
- Kah Hon Leong
- Department of Environmental Engineering, Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, 31900, Kampar, Perak, Malaysia
| | - Azrina Abd Aziz
- Faculty of Engineering Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, Gambang, 26300 Kuantan, Pahang, Malaysia
| | - Lan Ching Sim
- Department of Environmental Engineering, Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, 31900, Kampar, Perak, Malaysia
| | - Pichiah Saravanan
- Environmental Nanotechnology Laboratory, Department of Environmental Science and Engineering, Indian Institute of Technology (ISM) Dhanbad 826004, Jharkhand, India
| | - Min Jang
- Department of Environmental Engineering, Kwangwoon University, 447-1 Wolgye-Dong, Nowon-Gu, Seoul, South Korea
| | - Detlef Bahnemann
- Institut für Technische Chemie, Leibniz Universität Hannover, Callinstrasse 3, 30167 Hannover, Germany
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4
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Nosaka Y, Nosaka AY. Generation and Detection of Reactive Oxygen Species in Photocatalysis. Chem Rev 2017; 117:11302-11336. [DOI: 10.1021/acs.chemrev.7b00161] [Citation(s) in RCA: 1754] [Impact Index Per Article: 250.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Yoshio Nosaka
- Department of Materials Science
and Technology, Nagaoka University of Technology Nagaoka 940-2188, Japan
| | - Atsuko Y. Nosaka
- Department of Materials Science
and Technology, Nagaoka University of Technology Nagaoka 940-2188, Japan
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5
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Huang H, Dong F, Tian Y. Mitochondria-Targeted Ratiometric Fluorescent Nanosensor for Simultaneous Biosensing and Imaging of O2•– and pH in Live Cells. Anal Chem 2016; 88:12294-12302. [DOI: 10.1021/acs.analchem.6b03470] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Hong Huang
- Shanghai State
Key Laboratory
of Green Chemistry and Chemical
Processes, Department of Chemistry, East China Normal University, Dongchuan Road 500, Shanghai 200241, China
| | - Fangyuan Dong
- Shanghai State
Key Laboratory
of Green Chemistry and Chemical
Processes, Department of Chemistry, East China Normal University, Dongchuan Road 500, Shanghai 200241, China
| | - Yang Tian
- Shanghai State
Key Laboratory
of Green Chemistry and Chemical
Processes, Department of Chemistry, East China Normal University, Dongchuan Road 500, Shanghai 200241, China
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6
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Malek B, Fang W, Abramova I, Walalawela N, Ghogare AA, Greer A. “Ene” Reactions of Singlet Oxygen at the Air–Water Interface. J Org Chem 2016; 81:6395-401. [DOI: 10.1021/acs.joc.6b01030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Belaid Malek
- Department
of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York 11210, United States
| | - William Fang
- Department
of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York 11210, United States
| | - Inna Abramova
- Department
of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York 11210, United States
| | - Niluksha Walalawela
- Department
of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York 11210, United States
- Ph.D.
Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| | - Ashwini A. Ghogare
- Department
of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York 11210, United States
- Ph.D.
Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| | - Alexander Greer
- Department
of Chemistry, Brooklyn College of the City University of New York, Brooklyn, New York 11210, United States
- Ph.D.
Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
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7
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Buchalska M, Kobielusz M, Matuszek A, Pacia M, Wojtyła S, Macyk W. On Oxygen Activation at Rutile- and Anatase-TiO2. ACS Catal 2015. [DOI: 10.1021/acscatal.5b01562] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marta Buchalska
- Faculty
of Chemistry, Jagiellonian University in Kraków, Ingardena
3, 30-060 Kraków, Poland
| | - Marcin Kobielusz
- Faculty
of Chemistry, Jagiellonian University in Kraków, Ingardena
3, 30-060 Kraków, Poland
| | - Anna Matuszek
- Faculty
of Chemistry, Jagiellonian University in Kraków, Ingardena
3, 30-060 Kraków, Poland
- Department
of Chemistry, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Michał Pacia
- Faculty
of Chemistry, Jagiellonian University in Kraków, Ingardena
3, 30-060 Kraków, Poland
| | - Szymon Wojtyła
- Faculty
of Chemistry, Jagiellonian University in Kraków, Ingardena
3, 30-060 Kraków, Poland
| | - Wojciech Macyk
- Faculty
of Chemistry, Jagiellonian University in Kraków, Ingardena
3, 30-060 Kraków, Poland
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8
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Rajh T, Dimitrijevic NM, Bissonnette M, Koritarov T, Konda V. Titanium Dioxide in the Service of the Biomedical Revolution. Chem Rev 2014; 114:10177-216. [DOI: 10.1021/cr500029g] [Citation(s) in RCA: 222] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Tijana Rajh
- Center
for Nanoscale Materials, Argonne National Laboratory, 9700 South
Cass Avenue, Argonne, Illinois 60540, United States
| | - Nada M. Dimitrijevic
- Center
for Nanoscale Materials, Argonne National Laboratory, 9700 South
Cass Avenue, Argonne, Illinois 60540, United States
| | - Marc Bissonnette
- Department
of Medicine, The University of Chicago Medicine, 5841 South Maryland Avenue, MC 4076, Chicago, Illinois 60637, United States
| | - Tamara Koritarov
- Center
for Nanoscale Materials, Argonne National Laboratory, 9700 South
Cass Avenue, Argonne, Illinois 60540, United States
- School
of Medicine, Boston University, 72 East Concord Street, Boston, Massachusetts 02118, United States
| | - Vani Konda
- Department
of Medicine, The University of Chicago Medicine, 5841 South Maryland Avenue, MC 4076, Chicago, Illinois 60637, United States
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9
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Abstract
To detect singlet oxygen ((1)O2), the commercially available fluorescent sensor named Singlet Oxygen Sensor Green (SOSG) has been the most widely used from material studies to medical applications, for example, photodynamic therapy. In light of the previous studies, SOSG is a dyad composed of fluorescein and anthracene moieties. In the present study, we carried out quantitative studies on photochemical dynamics of SOSG for the first time, such as the occurrence of intramolecular photoinduced electron transfer (PET), (1)O2 generation, and two-photon ionization. It was revealed that these relaxation pathways strongly depend on the irradiation conditions. The visible-light excitation (ex. 532 nm) of SOSG induced intramolecular PET as a major deactivation process (kPET = 9.7 × 10(11) s(-1)), resulting in fluorescence quenching. In addition, intersystem crossing occurred as a minor deactivation process that gave rise to (1)O2 generation via the bimolecular triplet-triplet energy transfer (kq = 1.2 × 10(9) M(-1) s(-1)). Meanwhile, ultraviolet-light excitation (355 nm) of SOSG caused the two-photon ionization to give a SOSG cation (Φion = 0.003 at 24 mJ cm(-2)), leading to SOSG decomposition to the final products. Our results clearly demonstrate the problems of SOSG, such as photodecomposition and (1)O2 generation. In fact, these are not special for SOSG but common drawbacks for most of the fluorescein-based sensors.
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Affiliation(s)
- Sooyeon Kim
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University , Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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10
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Buchalska M, Łabuz P, Bujak Ł, Szewczyk G, Sarna T, Maćkowski S, Macyk W. New insight into singlet oxygen generation at surface modified nanocrystalline TiO2 – the effect of near-infrared irradiation. Dalton Trans 2013; 42:9468-75. [DOI: 10.1039/c3dt50399b] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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11
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Rozhkova EA, Ulasov IV, Kim DH, Dimitrijevic NM, Novosad V, Bader SD, Lesniak MS, Rajh T. MULTIFUNCTIONAL NANO-BIO MATERIALS WITHIN CELLULAR MACHINERY. INTERNATIONAL JOURNAL OF NANOSCIENCE 2012; 10:899. [PMID: 23105163 DOI: 10.1142/s0219581x11009350] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Functional nanoscale materials that possess specific physical or chemical properties can leverage energy transduction in vivo. Once these materials integrate with biomolecules they combine physical properties of inorganic material and the biorecognition capabilities of bio-organic moieties. Such nano-bio hybrids can be interfaced with living cells, the elementary functional units of life. These nano-bio systems are capable of bio-manipulation or actuation via altering intracellular biochemical pathways. Thus, nano-bio conjugates are appealing for a wide range of applications from the life sciences and nanomedicine to catalysis and clean energy production. Here we highlight recent progress in our efforts to develop smart nano-bio hybrid materials, and to study their performance within cellular machinery under application of external stimuli, such as light or magnetic fields.
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Affiliation(s)
- E A Rozhkova
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, USA
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12
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Li Z, Mi L, Wang PN, Chen JY. Study on the visible-light-induced photokilling effect of nitrogen-doped TiO2 nanoparticles on cancer cells. NANOSCALE RESEARCH LETTERS 2011; 6:356. [PMID: 21711880 PMCID: PMC3211446 DOI: 10.1186/1556-276x-6-356] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 04/21/2011] [Indexed: 05/23/2023]
Abstract
Nitrogen-doped TiO2 (N-TiO2) nanoparticles were prepared by calcining the anatase TiO2 nanoparticles under ammonia atmosphere. The N-TiO2 showed higher absorbance in the visible region than the pure TiO2. The cytotoxicity and visible-light-induced phototoxicity of the pure- and N-TiO2 were examined for three types of cancer cell lines. No significant cytotoxicity was detected. However, the visible-light-induced photokilling effects on cells were observed. The survival fraction of the cells decreased with the increased incubation concentration of the nanoparticles. The cancer cells incubated with N-TiO2 were killed more effectively than that with the pure TiO2. The reactive oxygen species was found to play an important role on the photokilling effect for cells. Furthermore, the intracellular distributions of N-TiO2 nanoparticles were examined by laser scanning confocal microscopy. The co-localization of N-TiO2 nanoparticles with nuclei or Golgi complexes was observed. The aberrant nuclear morphologies such as micronuclei were detected after the N-TiO2-treated cells were irradiated by the visible light.
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Affiliation(s)
- Zheng Li
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China
| | - Lan Mi
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China
| | - Pei-Nan Wang
- Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Department of Optical Science and Engineering, Fudan University, Shanghai 200433, China
| | - Ji-Yao Chen
- Surface Physics Laboratory (National Key Laboratory), Department of Physics, Fudan University, Shanghai 200433, China
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13
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Direct detection of OH radicals in the gas-phase diffused from the Pt/TiO2 and WO3/TiO2 photocatalysts under the UV-light irradiation. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2010.05.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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Lupton JM. Single-molecule spectroscopy for plastic electronics: materials analysis from the bottom-up. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:1689-721. [PMID: 20496402 DOI: 10.1002/adma.200902306] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
pi-conjugated polymers find a range of applications in electronic devices. These materials are generally highly disordered in terms of chain length and chain conformation, besides being influenced by a variety of chemical and physical defects. Although this characteristic can be of benefit in certain device applications, disorder severely complicates materials analysis. Accurate analytical techniques are, however, crucial to optimising synthetic procedures and assessing overall material purity. Fortunately, single-molecule spectroscopic techniques have emerged as an unlikely but uniquely powerful approach to unraveling intrinsic material properties from the bottom up. Building on the success of such techniques in the life sciences, single-molecule spectroscopy is finding increasing applicability in materials science, effectively enabling the dissection of the bulk down to the level of the individual molecular constituent. This article reviews recent progress in single molecule spectroscopy of conjugated polymers as used in organic electronics.
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Affiliation(s)
- John M Lupton
- Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112, USA.
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15
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Rozhkova EA, Ulasov I, Lai B, Dimitrijevic NM, Lesniak MS, Rajh T. A high-performance nanobio photocatalyst for targeted brain cancer therapy. NANO LETTERS 2009; 9:3337-42. [PMID: 19640002 PMCID: PMC4019973 DOI: 10.1021/nl901610f] [Citation(s) in RCA: 174] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report pronounced and specific antiglioblastoma cell phototoxicity of 5 nm TiO(2) particles covalently tethered to an antibody via a dihydroxybenzene bivalent linker. The linker application enables absorption of a visible part of the solar spectrum by the nanobio hybrid. The phototoxicity is mediated by reactive oxygen species (ROS) that initiate programmed death of the cancer cell. Synchrotron X-ray fluorescence microscopy (XFM) was applied for direct visualization of the nanobioconjugate distribution through a single brain cancer cell at the submicrometer scale.
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Affiliation(s)
- Elena A Rozhkova
- The Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA.
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16
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Li W, Gandra N, Courtney SN, Gao R. Singlet Oxygen Production upon Two-Photon Excitation of TiO2in Chloroform. Chemphyschem 2009; 10:1789-93. [DOI: 10.1002/cphc.200900155] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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17
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Tachikawa T, Majima T. Single-molecule fluorescence imaging of TiO(2) photocatalytic reactions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:7791-802. [PMID: 19402603 DOI: 10.1021/la900790f] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Heterogeneous photocatalysts have both potential and demonstrated applications for use in the water-splitting reaction that produces hydrogen, the degradation of organic pollutants, the surface wettability conversion, etc. In this feature article, we have focused on the in-site observation of various reactive oxygen species (ROS), such as singlet oxygen ((1)O(2)) and the hydroxyl radical ((*)OH), generated by the photoexcitation of TiO(2) nanomaterials using single-molecule fluorescence spectroscopy. The spatially resolved photoluminescence (PL) imaging techniques enable us to determine the location of the (photo)catalytically active sites that are related to the heterogeneously distributed defects on the surface. We also present the results that revealed the formation and reaction dynamics of the photogenerated charge carriers in individual TiO(2) nanoparticles. Furthermore, we introduce the single-molecule single-mismatch detection of the nucleotide sequence upon the photoexcitation of a novel nanoconjugate consisting of TiO(2) and DNA on the basis of the mechanistic aspects. Notably, the present conjugates can recognize the difference in a single nucleotide. Consequently, this article provides a significant opportunity to understand the temporal and spatial distributions of ROS generated during the photoirradiation of TiO(2) nanomaterials and directly explore the microscopic world in many fields ranging from fundamental physics and chemistry to practical applications.
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Affiliation(s)
- Takashi Tachikawa
- The Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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18
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Mills A, Hepburn J, McFarlane M. A novel, fast-responding, indicator ink for thin film photocatalytic surfaces. ACS APPLIED MATERIALS & INTERFACES 2009; 1:1163-1165. [PMID: 20355907 DOI: 10.1021/am9001502] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
A new photocatalyst indicator ink based on methylene blue (MB) is described that allows the presence and activity of a thin (15 nm) photocatalytic film to be assessed in seconds. The ink is very stable (shelf life > 6 months) and the color change (blue to colorless) striking. The ink utilizes a sacrificial electron donor, glycerol, to trap the photogenerated holes, leaving the photogenerated electrons to react with MB to produce its reduced, leuco, form (LMB). The efficacy of the MB ink is due to the presence of acid in its formulation, which curtails significantly the otherwise usual, rapid reoxidation of LMB by ambient O2.
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19
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Dimitrijevic NM, Rozhkova E, Rajh T. Dynamics of Localized Charges in Dopamine-Modified TiO2 and their Effect on the Formation of Reactive Oxygen Species. J Am Chem Soc 2009; 131:2893-9. [DOI: 10.1021/ja807654k] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nada M. Dimitrijevic
- Center for Nanoscale Materials, and Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Elena Rozhkova
- Center for Nanoscale Materials, and Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439
| | - Tijana Rajh
- Center for Nanoscale Materials, and Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439
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20
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Chemburu S, Corbitt TS, Ista LK, Ji E, Fulghum J, Lopez GP, Ogawa K, Schanze KS, Whitten DG. Light-induced biocidal action of conjugated polyelectrolytes supported on colloids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:11053-62. [PMID: 18729335 DOI: 10.1021/la8016547] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
A series of water soluble, cationic conjugated polyelectrolytes (CPEs) with backbones based on a poly(phenylene ethynylene) repeat unit structure and tetraakylammonium side groups exhibit a profound light-induced biocidal effect. The present study examines the biocidal activity of the CPEs, correlating this activity with the photophysical properties of the polymers. The photophysical properties of the CPEs are studied in solution, and the results demonstrate that direct excitation produces a triplet excited-state in moderate yield, and the triplet is shown to be effective at sensitizing the production of singlet oxygen. Using the polymers in a format where they are physisorbed or covalently grafted to the surface of colloidal silica particles (5 and 30 microm diameter), we demonstrate that they exhibit light-activated biocidal activity, effectively killing Cobetia marina and Pseudomonas aeruginosa. The light-induced biocidal activity is also correlated with a requirement for oxygen suggesting that interfacial generation of singlet oxygen is the crucial step in the light-induced biocidal activity.
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Affiliation(s)
- Sireesha Chemburu
- Department of Chemical and Nuclear Engineering, University of New Mexico, Albuquerque, New Mexico 87131-1341, USA
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