Electrochemical behaviour of gold nanoparticles and Co tetraaminophthalocyanine on glassy carbon electrode
- Authors: Maringa, Audacity , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7306 , http://hdl.handle.net/10962/d1020383
- Description: We report on the electrodeposition of gold nanoparticles (AuNPs) onto the glassy carbon electrode (GCE) followed by polymerization of cobalt tetraamino phthalocyanine (CoPc(NH2)4) on top (represented as poly-CoPc(NH2)4-/AuNPs-GCE). The modified electrode where CoPc(NH2)4 is polymerized first followed by deposition of AuNPs is represented as AuNPs/poly-CoPc(NH2)4-GCE. In the absence of AuNPs, the electrode is represented as poly-CoPc(NH2)4-GCE or for AuNPs alone (AuNPs-GCE). The surface coverage was 1.5 × 10−9 mol cm−2 for AuNPs-GCE and 3.0 × 10−9 mol cm−2 for the rest of the modified electrodes. AuNPs/CoPc(NH2)4-GCE exhibited high electrocatalytic activity towards the oxidation of nitrite, with detection potential of 0.76 V. The catalytic rate constant of 3.96 × 107 cm3 mol−1 s−1 was obtained for nitrite oxidation. , Original publication is available at http://dx.doi.org/10.1016/j.electacta.2013.12.132
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Enhanced nonlinear optical properties of octa-substituted lead and cadmium phthalocyanines when embedded in poly(bisphenol A carbonate) as thin films
- Authors: Mkhize, Colin , Britton, Jonathan , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7320 , http://hdl.handle.net/10962/d1020565
- Description: This work presents photophysical and nonlinear optical properties of a novel Cd 2,3-[octakis{4-tert-butylphenoxyphthalocyanine}] (CdOtBPPc) and compare them with those of Pb 2,3-[octakis{4-tert-butylphenoxyphthalocyanine}] (PbOtBPPc). For both the CdOtBPPc and PbOtBPPc, third order imaginary susceptibility and second order hyperpolarizability values were found to be within the limit set for good optical limiters. The Pcs were embedded in poly (methyl methacrylate) (PMMA) and poly(bisphenol A carbonate) (PBC) as thin films. The optical limiting values of the Pcs once embedded in film were found to be greatly improved and the limiting fluence of each film was well below the maximum threshold. Both PbOtBPPc and CdOtBPPc showed better optical limiting when embedded in PBC compared to PMMA. CdOtBPPc shows better nonlinear optical behavior than PbOtBPPc in solution and as thin films, even though the former is aggregated in solution. , Original publication is available at http://dx.doi.org/10.1016/j.poly.2014.07.025
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Factors contributing to occupational stress in student support staff in a Further Education and Training (FET) College in the Southern Cape
- Authors: De Klerk, Ulricha
- Subjects: Work -- Psychological aspects , Job stress -- South Africa -- Western Cape , College students -- South Africa -- Western Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10085 , http://hdl.handle.net/10948/d1020806
- Description: The main purpose of this study is to explore the factors that contribute to occupational stress as experienced by the Student Support staff in a Further Education and Training (FET) College in the Southern Cape. The Student Support staff has displayed many symptoms of stress over the past few years. This in turn has led to absenteeism, change in staff temperament, their feelings towards the College, motivation levels and a significant change in the staff’s day to day operations. Although the Head of Department for Student Support Services has engaged with the staff on numerous occasions to discuss the reasons for their experience of stress, no substantial reasons could be established in order to make the necessary changes in the department. No interventions that have been implemented to date have relieved the staff’s experience of stress. The researcher chose to use a qualitative, exploratory, descriptive and contextual research design to gain insight into the situation or phenomenon in order to identify the factors contributing to occupational stress and to identify measures that can be implemented to reduce occupational stress in the Student Support staff. The participants in this research included at least 10 Student Support staff within the Student Support Services Department at a Further Education and Training College in the Southern Cape. Purposive sampling was used in this research study. Interviews will continue until data saturation is achieved. The staff members must have been employed for at least one year in the Student Support Services Department. The researcher will make use of semi-structured interviews, observations and field notes. The data will be systematically collected and meanings, themes and general descriptions of the experience analysed within the specific context (de Vos, Strydom, Fouche & Delport, 2005). The researcher will make use of Tesch’s method of analysis, and use Guba’s strategies for ensuring Trustworthiness. The researcher will apply the ethical considerations of confidentiality, informed consent, ethical approval from relevant institutions, avoidance of harm to participants, truthfulness and the debriefing of participants when conducting this study. The findings were reported as three major themes and subthemes. The three major themes were; Student support staff identified several factors that contributed to occupational stress, Student support staff identified the effect that occupational stress has on them, Student support staff offered suggestions that the college could implement to reduce occupational stress. These themes were discussed and analysed in-depth.
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Grounds & gardens : adding value to the living space : "Enabling the Academic Project" : 26 years on the greenside
- Authors: Hazell, M
- Language: English
- Type: Text
- Identifier: vital:7959 , http://hdl.handle.net/10962/d1008354
- Description: [A presentation given by Mark Hazell, Manager: Grounds & Gardens at Rhodes University, to the Rhodes University Environmental Committee on the occasion of his retirement from Rhodes University]
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Improved l-cysteine electrocatalysis through a sequential drop dry technique using multi-walled carbon nanotubes and cobalt tetraaminophthalocyanine conjugates
- Authors: Nyoni, Stephen , Mugadza, Tawanda , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7308 , http://hdl.handle.net/10962/d1020385
- Description: Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for characterization of a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs)–cobalt tetraaminophthalocyanine (CoTAPc) mixture or sequential drop dry modification technique whereby the MWCNTs are first placed on to the electrode followed by CoTAPc. The sequential drop dry CoTAPc–MWCNTs modified surface gave better catalytic responses with a catalytic rate constant of 2.2 × 105 M−1 s−1, apparent electron transfer rate constant of 0.073 cm s−1, and a limit of detection of 2.8 × 10−7 M. Scanning electrochemical microscopy (SECM) surface characterization (topography and reactivity) further gave proof the better catalytic perfomance of the sequential drop dry CoTAPc–MWCNTs modified surface. , Original publication is available at http://dx.doi.org/10.1016/j.electacta.2013.10.023
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Job satisfaction amongst middle managers of Department of Health
- Authors: Mawonga, Mzukisi Edward
- Subjects: Job satisfaction -- South Africa -- Eastern Cape , Job stress -- South Africa -- Eastern Cape. , Middle managers -- Job satisfaction , Public health administration -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10082 , http://hdl.handle.net/10948/d1020197
- Description: Job satisfaction studies are an essential element for ensuring improvement in service delivery. The researcher was committed to assist top management with important information that can make them aware of the causes and consequences of job satisfaction (Nel, Van Dyk, Haasbroek, Schultz, Sono and Werner, 2006:52). Job satisfaction is not only concerned with feeling good at work, it also encompasses job content, the work environment and interaction with all people. The study was conducted at the Department of Health in the Province of the Eastern Cape. This study aimed to describe the level of job satisfaction amongst middle managers of the Department of Health (DoH) at the Head Office, in terms of remuneration, interpersonal relationships, development, support, recognition, extent of supervision, their attitude to the work itself and working conditions.
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Local economic development: disseminating global best practices to affect futuristic thinking in SA
- Authors: Perks, Sandra
- Subjects: Economic development , Economic development -- South Africa , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20966 , vital:29423
- Description: The aim of Local Economic Development (LED) is to ensure that the economy of a community, region or country grows faster than the population, so that there can be surplus resources for future expansion (Rucker, Kinnett & Barbash 2012). This suggests that LED is more than economic development at local level. LED is often not viewed from an economic perspective but from a political perspective. Birkhölzer (2005:3) outlines four possible political LED viewpoints. The first perspective is “development from above” with an authoritarian state dictating to regional government and local authorities. This perspective has been proven flawed when political or economic turbulences occur. The second perspective is “development from outside” with reliance on outside investors to bring into the country the necessary resources, mostly funding. This perspective is risky from a sustainability point of view. The third perspective is the “wait and see” where migration occurs if there are problems. This perspective is equally flawed as it is becoming increasingly difficult to migrate because it is so costly, and also finding the right place to go can prove to be problematic. The last perspective is the “development from within” where people play a key role, and do not rely on government or the economy to serve their needs or solve their problems; this points to self-sufficiency.
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Nurse managers' perceptions of the Eastern Cape department of health employee assistance programme
- Authors: Stenge, Nyameka
- Subjects: Employee assistance programs -- South Africa -- Eastern Cape , Nurse administrators -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10088 , http://hdl.handle.net/10948/d1021203
- Description: Organizations assist employees to deal effectively with demanding work and the work environment, including their personal problems, through an Employee Assistance Programme (EAP). The essence of the EAP is the application of knowledge about behaviour and behavioural health to make accurate assessments, followed by appropriate action to improve the productivity and healthy functioning of the employees. According to the report from the Employee Wellness Directorate of the Eastern Cape, the Employee Assistance Programme Practitioners saw 576 employees in 2010. These statistics only represent a few districts in the Eastern Cape as some districts do not have Employee Assistance Practitioners offering employee assistance, hence this number could be higher. In some instances employees do self-referral, which may increase the number without the managers knowing who is utilizing the EAP. This makes it difficult for the managers to monitor such employees and the effectiveness of the intervention rendered. Managers refer employees but do not have control over whether employees made use of the EAP and on the progress in sessions as they do not always receive the feedback. The Employee Assistance counsellor may receive a written referral from the nursing manager and then consults the referred employee in private. The employee gives consent and then the EAP counsellor addresses the problem at hand. If it is a complex case needing expert intervention arrangements are made. If the intervention requires follow up sessions, the EAP counsellor makes the necessary arrangements through the referring manager until the problem is resolved. The EAP counsellor monitors the employee and asks the manager to support the employee without divulging details of the problem that was being addressed. However, the Nursing Managers do not know how effective the programme is and whether the employees benefit from the use. The above-mentioned problem led the researcher to ask the following questions: • What are the perceptions that Nurse Managers in the Department of Health in the Eastern Cape Province have of the effectiveness of the Employee Assistance Programme? • How can Nurse Managers optimize employees’ use of the EAP? The goal of this study was to identify the perceptions of Nurse Managers of the Employee Assistance Programme in order to determine how the programme’s use can be optimized. The researcher used a qualitative, explorative, descriptive and contextual design. The research population was selected purposively and included the Nursing Managers in the Department of Health in the Chris Hani District, Eastern Cape, who have referred employees to the Employee Assistance Programme. Semi-structured interviews were used during the data gathering process. Interviews were conducted at a venue convenient to the participants. Open-ended questions were asked to enable participants to express their perceptions on the topic. The researcher also used observation and field-notes to ensure that the data gathering provided rich information. The data was analysed using Tesch’s method of data analysis. Trustworthiness was ensured by using Guba’s model of trustworthiness. The ethical strategies of informed consent, confidentiality and anonymity, avoidance of harm and voluntary participation were ensured. Two themes emerged from the data analysis. Theme one showed that the participants had contrasting perceptions regarding the effectiveness of the current Employee Assistance Programme. Some felt that they have benefitted from the programme while others felt differently. Theme two described the participants’ views elated to improving the utilization of the EAP. Positive and negative factors that impacted on the implementation of EAP have been identified. Results show that both the employer and the employees could benefit if EAP is well implemented. Decentralization of EAP could be very cost effective and could save the employer thousands of rands because resources would be utilized better.
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Optical nonlinearities and photophysicochemical behaviour of green and blue forms of lutetium bisphthalocyanines
- Authors: Sekhosana, Kutloano Edward , Amuhaya, Edith , Mack, John , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7316 , http://hdl.handle.net/10962/d1020543
- Description: A rare earth sandwich-type phthalocyanine: bis-{2,3,9,10,16,17,23,24-octa(4-tert-butylphenoxy) phthalocyaninato} lutetium(III) has been synthesized. The photophysical and nonlinear optical behavior of both the “green” and “blue” forms ([LuIIIPc2] and [LuIIIPc2]−, respectively) of the complex have been investigated. High triplet state and singlet oxygen quantum yield values were obtained for the neutral blue form which contains no unpaired electrons. Relatively high third order susceptibility and hyperpolarizability values of the order of 10−10 and 10−28 esu were obtained for both the green and blue forms, respectively. A very low threshold intensity of 0.00051 J cm−2 was obtained for the blue form. Hence the complex shows promise for non-linear optical applications. , Original publication is available at http://dx.doi.org/10.1039/C4TC00505H
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Optical nonlinearities in non-peripherally substituted pyridyloxy phthalocyanines: a combined effect of symmetry, ring-strain and demetallation
- Authors: Sanusi, Kayode , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7301 , http://hdl.handle.net/10962/d1020375
- Description: The optical nonlinearities of six non-peripherally-substituted pyridyloxy phthalocyanines have been studied at 532 nm using a nanosecond Z-scan technique in a dimethyl sulphoxide solution. Ring-strain effects and the absence of a metal center were found to greatly reduce the inherent high nonlinearities expected of some of these phthalocyanine complexes. Of the six molecules investigated, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyaninato lead(II) 3, 1(4),8(11),15(18),22(25)-tetrakis-(2-pyridyloxy)phthalocyanine 5, and 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyanine 6 were found to exhibit negligible nonlinear optical behavior, due to either the absence of asymmetry or central metal and/or the presence of a ring-strain effect. A two-photon absorption process was found to be the major contributor to the observed reverse saturable absorption (RSA) in 1(4),8(11),15(18),22(25)-tetrakis-(4-pyridyloxy)phthalocyaninato lead(II) 4, 1(4)-mono-(2-pyridyloxy)phthalocyaninato lead(II) 7, and 1(4)-mono-(4-pyridyloxy)phthalocyaninato lead(II) 8, with large two-photon absorption cross-section, high hyperpolarizability and high third-order susceptibility values in the range of 4.53 × 10−43–5.33 × 10−42 cm4 s per photon, 1.61 × 10−28–1.89 × 10−27 esu and 9.73 × 10−12–7.05 × 10−11 esu respectively. , Original publication is available at http://dx.doi.org/10.1039/C3DT52462K , Arbortext Advanced Print Publisher 9.1.520/W Unicode , Acrobat Distiller 10.0.0 (Windows); modified using iText� 5.3.3 �2000-2012 1T3XT BVBA (AGPL-version)
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Photocatalytic behavior of phthalocyanine-silver nanoparticle conjugates supported on polystyrene fibers
- Authors: Khoza, Phindile , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7317 , http://hdl.handle.net/10962/d1020561
- Description: Herein, carbazole derivatized non-peripheral (1,(4)-tetra(carbazol-2-yloxy)phthalocyaninatozinc(II), 3-TCbZnPc) and peripheral (2,(3)-tetra(carbazol-2-yloxy)phthalocyaninato zinc(II), 4-TCbZnPc) are conjugated to silver nanoparticles and their photochemical and photophysical behavior are reported. The presence of silver nanoparticles resulted in reduced fluorescence, and increased triplet and singlet oxygen quantum yields. The conjugates were further electrospun into polystyrene fibers, and employed for the photodegradation of methyl orange. The photodegradation of methyl orange using all functionalized fibers followed first order kinetics, and was faster when the conjugates with silver nanoparticles were used. The non-peripherally substituted 3-TCbZnPc gave better photocatalytic activity compared to its peripherally substituted counterpart (4-TCbZnPc). The hybrid electrospun fibers provide great potential as active photocatalysts for degrading organic pollutants. , Online publication is available at http://dx.doi.org/10.1016/j.molcata.2014.07.031
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Photophysichochemical behavior of carbazole derivatized zinc phthalocyanine in the presence of ZnO microparticles and when embedded in electrospun fibers
- Authors: Khoza, Phindile , Antunes, Edith M , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7303 , http://hdl.handle.net/10962/d1020380
- Description: The synthesis of a zinc phthalocyanine complex tetrasubstituted with carbazole functionality at the peripheral position (complex 4) is reported. The singlet oxygen quantum yield of the complex was found to be 0.83 in dimethylformamide (DMF). The complex was subsequently conjugated to zinc oxide microparticles (ZnOMPs), the conjugation (formation of the amide bond) was confirmed by IR spectroscopy. The presence of ZnOMPs was found to reduce the singlet oxygen produced (ΦΔ = 0.63) in DMF. Polystyrene electrospun fibers of complex 4 alone and its conjugate to ZnOMPs were found to be thermally stable. The singlet oxygen quantum yield of the modified electrospun fibers was determined in aqueous media with ADMA as a singlet oxygen quencher and were 0.25 and 0.20 for complex 4 and 4-ZnOMPs embedded in fibers, respectively. , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2013.12.019
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Polyamide nanofiber membranes functionalized with zinc phthalocyanines
- Authors: Goethals, Annelies , Mugadza, Tawanda , Arslanoglu, Yasin , Zugle, Ruphino , Antunes, Edith M , Hulle, Stijn W H Van , Nyokong, Tebello , Clerck, Karen De
- Language: English
- Type: Article
- Identifier: vital:7313 , http://hdl.handle.net/10962/d1020539
- Description: Electrospinning is an efficient method for the production of polyamide nanofiber membranes that are suitable for water filtration. Previous studies have shown that nanofiber membranes have high clean water permeability. The pathogen removal efficiency can be improved by functionalization with (organic) biocides. However, these membranes, like other membranes, are vulnerable to fouling which reduces the filtration efficiency. Therefore the present article investigates the potential of zinc phthalocyanines, which can produce singlet oxygen in the presence of visible light, as a functionalizing agent. The polyamide nanofiber membranes were functionalized with phthalocyanines using both a pre-functionalizing and post-functionalizing method. Only the post-functionalization method shows to result in nanofiber membranes capable of producing singlet oxygen. After 30 min 45% of 1,2-diphenylisobenzofuran (DPBF), used as an oxygen quencher, was removed by reaction with singlet oxygen. This resulted in a removal rate of 0.33 mol DBPF mol−1Zn min−1. During short term leaching tests, phthalocyanines could not be detected. , Original publication is available at http://dx.doi.org/10.1002/app.40486
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Resource nationalism: a threat or a panacea to economic development
- Authors: Ocran, Matthew
- Subjects: Natural resources , Nationalism , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20901 , vital:29412
- Description: I seek to achieve three objectives in my lecture: first I attempt an outline of the evolution of economic thought regarding progress from the medieval period to contemporary times. Following the discussion of the mainstream theories of economic growth I then review the associated empirical literature. I also consider a brief case study on two successful countries before addressing the question whether resource nationalism matter in determining economic development. Lastly, I provide some policy recommendations for economic development in South Africa and other resource rich countries on the continent.
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SEK Mqhayi in the 21st Century: Mzantsi youth ideologies within the African renaissance paradigm for sustainable economic and political development
- Authors: Saule, Ncedile
- Subjects: Pan-Africanism , Mqhayi, S E K , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/21011 , vital:29427
- Description: I am advancing a celebratory synopsis of Mqhayi, uMzima, uBhomoyi kaCedume at a time when the South African contemporary society is attempting to restructure itself in order to regain lost values before it can successfully and rationally embrace values of other people. In my presentation, I have mindfully taken cognisance of the plight of the so called lost generation, especially among our youth, those who have become strangers in their own land – no language, only misguided and distorted cultural values, no self, distorted history - this of course because of indoctrinations of some psycho-socio-histori-cultural and political imperatives. Strangely enough these are some of the issues that SEK Mqhayi warns us about in his creative works and has made efforts for us to see, but unfortunately no one listened or saw anything. Now that we “have the truth but denied the truth and now that we have the light, but we sit in darkness, Shivering, benighted in the bright noon-day sun,” and now that we are all blind, I think, this evening is the right time to see.
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South African estuaries in the Anthropocene
- Authors: Perissinotto, Renzo
- Subjects: Estuaries -- South Africa , Geology, Stratigraphic -- Anthropocene , f-sa
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/10948/20977 , vital:29424
- Description: In the new geological epoch of total human dominance of the planet, already widely referred to as the “Anthropocene”, estuaries are among the most vulnerable ecosystems to the changes that man’s activities have imposed on the coastal zone. For the non-specialist, an estuary is a “semi-enclosed coastal body of water, which has a permanent or temporary connection with the open sea, and within which sea water is diluted with fresh water from land drainage”.
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Spectral properties and photophysical behaviour of water soluble cationic Mg(II) and Al(III) phthalocyanines
- Authors: Idowu, Mopelola A , Arslanoglu, Yasin , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7277 , http://hdl.handle.net/10962/d1020292
- Description: Peripherally and non-peripherally tetrasubstituted-[(N-methyl-2-pyridylthio)]phthalocyaninato magnesium (II) (5 and 6) and chloro aluminium (III) (7 and 8) tetraiodide have been synthesized and characterized. The photophysical properties of the complexes in dimethyl sulfoxide (DMSO) and aqueous medium in the presence and absence of cremophore EL have been studied. These complexes show high solubility in aqueous medium though they were aggregated. The triplet state quantum yields (FT) and the triplet lifetimes (tT) were found to be higher in DMSO with ΦT ranging from 0.32 to 0.51, while tT ranged from 282 to 622 ms in DMSO, compared to aqueous medium (pH 7.4 buffer) where ΦT ranged from 0.15 to 0.19 and tT from 26 to 35 ms. Addition of cremophore EL in aqueous solution resulted in partial disaggregation and increased photoactivity. The fluorescence lifetimes of the complexes showed strong dependence on their immediate environment. The ionic magnesium(II) and aluminium(III) phthalocyanines strongly bind to bovine serum albumin (BSA). , Original publication is available at http://dx.doi.org/10.2478/s11532-013-0388-z
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Synthesis and characterization of quantum dots designed for biomedical use
- Authors: Kuzyniak, Weronika , Adegoke, Oluwasesan , Sekhosana, Kutloano , D’Souza, Sarah , Tshangana, Sesethu Charmaine , Hoffmann, Björn , Ermilov, Eugeny A. , Nyokong, Tebello , Höpfner, Michael
- Language: English
- Type: Article
- Identifier: vital:7310 , http://hdl.handle.net/10962/d1020387
- Description: Semiconductor quantum dots (QDs) have become promising nanoparticles for a wide variety of biomedical applications. However, the major drawback of QDs is their potential toxicity. Here, we determined possible cytotoxic effects of a set of QDs by systematic photophysical evaluation in vitro as well as in vivo. QDs were synthesized by the hydrothermal aqueous route with sizes in the range of 2.0–3.5 nm. Cytotoxic effects of QDs were studied in the human pancreatic carcinoid cell line BON. Cadmium telluride QDs with or without zinc sulfide shell and coated with 3-mercaptopropionic acid (MPA) were highly cytotoxic even at nanomolar concentrations. Capping with l-glutathione (GSH) or thioglycolic acid (TGA) reduced the cytotoxicity of cadmium telluride QDs and cadmium selenide QDs. Determination of the toxicity of QDs revealed IC50 values in the micromolar range. In vivo studies showed good tolerability of CdSe QDs with ZnS shell and GSH capping. We could demonstrate that QDs with ZnS shell and GSH capping exhibit low toxicity and good tolerability in cell models and living organisms. These QDs appear to be promising candidates for biomedical applications such as drug delivery for enhanced chemotherapy or targeted delivery of light sensitive substances for photodynamic therapy. , Original publication is available at http://dx.doi.org/10.1016/j.ijpharm.2014.03.037
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Unsymmetrically Substituted Nickel Triazatetra-Benzcorrole and Phthalocynanine Complexes: Conjugation to Quantum Dots and Applications as Fluorescent “Turn ON” Sensors
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7311 , http://hdl.handle.net/10962/d1020403
- Description: We report on the design and application of fluorescent nanoprobes based on the covalent linking of L-glutathione-capped CdSe@ZnS quantum dots (QDs) to newly synthesized unsymmetrically substituted nickel mercaptosuccinic acid triazatetra-benzcorrole (3) and phthalocyanine (4) complexes. Fluorescence quenching of the QDs occurred on conjugation to complexes 3 or 4. The nanoprobes were selectively screened in the presence of different cations and Hg2+ showed excellent affinity in “turning ON” the fluorescence of the nanoprobes. Experimental results showed that the sensitivity of QDs-4 towards Hg2+ was much higher than that of QDs-3 nanoprobe. The mechanism of reaction has been elucidated based on the ability of Hg2+ to coordinate with the sulphur atom of the Ni complex ring and apparently “turn ON” the fluorescence of the linked QDs. , Original publication is available at http://dx.doi.org/10.1007/s10895-013-1317-4
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