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  1. Plasmon enhanced organic devices utilizing highly ordered nanoimprinted gold nanodisks and nitrogen doped graphene
    Teridi MA, Sookhakian M, Basirun WJ, Zakaria R, Schneider FK, da Silva WJ, et al.
    Nanoscale, 2015 Apr 28;7(16):7091-100.
    PMID: 25640454 DOI: 10.1039/c4nr05874g
    High performance organic devices including polymer solar cells (PSCs) and light emitting diodes (PLEDs) were successfully demonstrated with the presence of highly ordered nanoimprinted Au nanodisks (Au NDs) in their solution-processed active/emissive layers, respectively. PSCs and PLEDs were fabricated using a low bandgap polymer and acceptor, nitrogen doped multiwalled carbon nanotubes poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno[3,4-b]-thiophenediyl] (n-MWCNTs:PTB7), and [6,6]-phenyl C71 butyric acid methyl ester (PC71BM) and (4,4-N,N-dicarbazole) biphenyl (CBP) doped with tris(2-phenylpyridine) iridium(iii) (Ir(ppy)3) as active/emissive layers, respectively. We synthesized nitrogen doped graphene and used it as anodic buffer layer in both devices. The localized surface plasmon resonance (LSPR) effect from Au NDs clearly contributed to the increase in light absorption/emission in the active layers from electromagnetic field enhancement, which originated from the excited LSPR in PSCs and PLEDs. In addition to the high density of LSPR and strong exciton-SP coupling, the electroluminescent (EL) enhancement is ascribed to enhanced spontaneous emission rates. This is due to the plasmonic near-field effect induced by Au NDs. The PSCs and PLEDs exhibited 14.98% (8.08% to 9.29%) under one sun of simulated air mass 1.5 global (AM1.5G) illumination (100 mW cm(-2)) and 19.18% (8.24 to 9.82 lm W(-1)) enhancement in the power conversion efficiencies (PCEs) compared to the control devices without Au NDs.
  2. Identification of naphthalene metabolism by white rot fungus Pleurotus eryngii
    Hadibarata T, Teh ZC, Rubiyatno, Zubir MM, Khudhair AB, Yusoff AR, et al.
    Bioprocess Biosyst Eng, 2013 Oct;36(10):1455-61.
    PMID: 23334282 DOI: 10.1007/s00449-013-0884-8
    The use of biomaterials or microorganisms in PAHs degradation had presented an eye-catching performance. Pleurotus eryngii is a white rot fungus, which is easily isolated from the decayed woods in the tropical rain forest, used to determine the capability to utilize naphthalene, a two-ring polycyclic aromatic hydrocarbon as source of carbon and energy. In the meantime, biotransformation of naphthalene to intermediates and other by-products during degradation was investigated in this study. Pleurotus eryngii had been incubated in liquid medium formulated with naphthalene for 14 days. The presence of metabolites of naphthalene suggests that Pleurotus eryngii begin the ring cleavage by dioxygenation on C1 and C4 position to give 1,4-naphthaquinone. 1,4-Naphthaquinone was further degraded to benzoic acid, where the proposed terepthalic acid is absent in the cultured extract. Further degradation of benzoic acid by Pleurotus eryngii shows the existence of catechol as a result of the combination of decarboxylation and hydroxylation process. Unfortunately, phthalic acid was not detected in this study. Several enzymes, including manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase are enzymes responsible for naphthalene degradation. Reduction of naphthalene and the presence of metabolites in liquid medium showed the ability of Pleurotus eryngii to utilize naphthalene as carbon source instead of a limited glucose amount.
  3. An Overview of the Recent Progress in Polymeric Carbon Nitride Based Photocatalysis
    Humayun M, Ullah H, Tahir AA, Bin Mohd Yusoff AR, Mat Teridi MA, Nazeeruddin MK, et al.
    Chem Rec, 2021 Jul;21(7):1811-1844.
    PMID: 33887089 DOI: 10.1002/tcr.202100067
    Recently, polymeric carbon nitride (g-C3 N4 ) as a proficient photo-catalyst has been effectively employed in photocatalysis for energy conversion, storage, and pollutants degradation due to its low cost, robustness, and environmentally friendly nature. The critical review summarized the recent development, fundamentals, nanostructures design, advantages, and challenges of g-C3 N4 (CN), as potential future photoactive material. The review also discusses the latest information on the improvement of CN-based heterojunctions including Type-II, Z-scheme, metal/CN Schottky junctions, noble metal@CN, graphene@CN, carbon nanotubes (CNTs)@CN, metal-organic frameworks (MOFs)/CN, layered double hydroxides (LDH)/CN heterojunctions and CN-based heterostructures for H2 production from H2 O, CO2 conversion and pollutants degradation in detail. The optical absorption, electronic behavior, charge separation and transfer, and bandgap alignment of CN-based heterojunctions are discussed elaborately. The correlations between CN-based heterostructures and photocatalytic activities are described excessively. Besides, the prospects of CN-based heterostructures for energy production, storage, and pollutants degradation are discussed.
  4. Fabrication, characterization and application of laccase-nylon 6,6/Fe(3+) composite nanofibrous membrane for 3,3'-dimethoxybenzidine detoxification
    Jasni MJ, Sathishkumar P, Sornambikai S, Yusoff AR, Ameen F, Buang NA, et al.
    Bioprocess Biosyst Eng, 2017 Feb;40(2):191-200.
    PMID: 27757535 DOI: 10.1007/s00449-016-1686-6
    In this study, laccase was immobilized on nylon 6,6/Fe(3+) composite (NFC) nanofibrous membrane and used for the detoxification of 3,3'-dimethoxybenzidine (DMOB). The average size and tensile strength of the NFC membrane were found to be 60-80 nm (diameter) and 2.70 MPa, respectively. The FTIR results confirm that the amine (N-H) group of laccase was attached with Fe(3+) particles and the carbonyl (C=O) group of NFC membrane via hydrogen bonding. The half-life of the laccase-NFC membrane storage stability was increased from 6 to 11 weeks and the reusability was significantly extended up to 43 cycles against ABTS oxidation. Enhanced electro-oxidation of DMOB by laccase was observed at 0.33 V and the catalytic current was found to be 30 µA. The DMOB-treated mouse fibroblast 3T3-L1 preadipocytes showed maximum (97 %) cell inhibition at 75 µM L(-1) within 24 h. The cytotoxicity of DMOB was significantly decreased to 78 % after laccase treatment. This study suggests that laccase-NFC membrane might be a good candidate for emerging pollutant detoxification.
  5. Fulltext Improving Performance of Electrospun Nylon 6,6 Nanofiber Membrane for Produced Water Filtration via Solvent Vapor Treatment
    Abd Halim NS, Wirzal MDH, Bilad MR, Md Nordin NAH, Adi Putra Z, Sambudi NS, et al.
    Polymers (Basel), 2019 Dec 17;11(12).
    PMID: 31861059 DOI: 10.3390/polym11122117
    Electrospun nanofiber membrane (NFM) has a high potential to be applied as a filter for produced water treatment due to its highly porous structure and great permeability. However, it faces fouling issues and has low mechanical properties, which reduces the performance and lifespan of the membrane. NFM has a low integrity and the fine mat easily detaches from the sheet. In this study, nylon 6,6 was selected as the polymer since it offers great hydrophilicity. In order to increase mechanical strength and separation performance of NFM, solvent vapor treatment was implemented where the vapor induces the fusion of fibers. The fabricated nylon 6,6 NFMs were treated with different exposure times of formic acid vapor. Results show that solvent vapor treatment helps to induce the fusion of overlapping fibers. The optimum exposure time for solvent vapor is 5 h to offer full retention of dispersed oil (100% of oil rejection), has 62% higher in tensile strength (1950 MPa) compared to untreated nylon 6,6 NFM (738 MPa), and has the final permeability closest to the untreated nylon 6,6 NFM (733 L/m2.h.bar). It also took more time to get fouled (220 min) compared to untreated NFM (160 min).
  6. Degradation and transformation of anthracene by white-rot fungus Armillaria sp. F022
    Hadibarata T, Zubir MM, Rubiyatno, Chuang TZ, Yusoff AR, Salim MR, et al.
    Folia Microbiol (Praha), 2013 Sep;58(5):385-91.
    PMID: 23307571 DOI: 10.1007/s12223-013-0221-2
    Characterization of anthracene metabolites produced by Armillaria sp. F022 was performed in the enzymatic system. The fungal culture was conducted in 100-mL Erlenmeyer flask containing mineral salt broth medium (20 mL) and incubated at 120 rpm for 5-30 days. The culture broth was then centrifuged at 10,000 rpm for 45 min to obtain the extract. Additionally, the effect of glucose consumption, laccase activity, and biomass production in degradation of anthracene were also investigated. Approximately, 92 % of the initial concentration of anthracene was degraded within 30 days of incubation. Dynamic pattern of the biomass production was affected the laccase activity during the experiment. The biomass of the fungus increased with the increasing of laccase activity. The isolation and characterization of four metabolites indicated that the structure of anthracene was transformed by Armillaria sp. F022 in two routes. First, anthracene was oxidized to form anthraquinone, benzoic acid, and second, converted into other products, 2-hydroxy-3-naphthoic acid and coumarin. Gas chromatography-mass spectrometry analysis also revealed that the molecular structure of anthracene was transformed by the action of the enzyme, generating a series of intermediate compounds such as anthraquinone by ring-cleavage reactions. The ligninolytic enzymes expecially free extracellular laccase played an important role in the transformation of anthracene during degradation period.
  7. Composition of deposited sediment and its temporal variation in a disturbed tropical catchment in the Kelantan river basin, Peninsular Malaysia
    Sugumaran D, Blake WH, Millward GE, Yusop Z, Mohd Yusoff AR, Mohamad NA, et al.
    Environ Sci Pollut Res Int, 2023 Jun;30(28):71881-71896.
    PMID: 35411514 DOI: 10.1007/s11356-022-19904-6
    Pristine tropical river systems are coming under increasing pressure from the development of economic resources such as forestry and mining for valuable elements. The Lebir catchment, north eastern Malaysia, is now under development as a result of unregulated tree felling and mining for essential and rare metals. Two sediment cores, one in the upstream reaches and the other from the downstream reaches, were taken from flood prone area of the Lebir River, Malaysia, and analysed for their elemental composition by XRF, specifically Al, Si, Fe, Ca, K, Mg, Mn, V, Cu, Ni, Pb, Cr, Zn, As, Th and U. Activities of fallout radionuclides, 137Cs and 210Pb were also determined to from a geochronological context. The elemental concentrations in the soils were assessed in terms of their enrichment factor and Si, Ca, K, Mg, Mn, V, Cu, Ni and Zn were found not to be enriched, whereas As, Th and U had elevated enrichment factors. The Th and U were particularly enriched in the downstream core indicating inputs from a tributary that drains a catchment with known deposits of Th and possibly U. The results suggest that the growth in economic development is fostering the transport of contaminants by the major rivers which, in turn, is contaminating the riverine floodplains. This points to the need for a more integrated and holistic approach to river basin management to maintain the environmental quality of these fragile aquatic systems.
  8. Photocatalytic activity and reusability of ZnO layer synthesised by electrolysis, hydrogen peroxide and heat treatment
    Akhmal Saadon S, Sathishkumar P, Mohd Yusoff AR, Hakim Wirzal MD, Rahmalan MT, Nur H
    Environ Technol, 2016 Aug;37(15):1875-82.
    PMID: 26732538 DOI: 10.1080/09593330.2015.1135989
    In this study, the zinc oxide (ZnO) layer was synthesised on the surface of Zn plates by three different techniques, i.e. electrolysis, hydrogen peroxide and heat treatment. The synthesised ZnO layers were characterised using scanning electron microscopy, X-ray diffraction, UV-visible diffuse reflectance and photoluminescence spectroscopy. The photocatalytic activity of the ZnO layer was further assessed against methylene blue (MB) degradation under UV irradiation. The photocatalytic degradation of MB was achieved up to 84%, 79% and 65% within 1 h for ZnO layers synthesised by electrolysis, heat and hydrogen peroxide treatment, respectively. The reusability results show that electrolysis and heat-treated ZnO layers have considerable photocatalytic stability. Furthermore, the results confirmed that the photocatalytic efficiency of ZnO was directly associated with the thickness and enlarged surface area of the layer. Finally, this study proved that the ZnO layers synthesised by electrolysis and heat treatment had shown better operational stability and reusability.
  9. Fulltext Cholangiocarcinoma: a 10-year experience of a single tertiary centre in the multi ethnicity-Malaysia
    Yusoff AR, Siti ZM, Muzammil ARM, Yoong BK, Vijeyasingam R
    Med J Malaysia, 2012 Feb;67(1):45-51.
    PMID: 22582548 MyJurnal
    Cholangiocarcinoma (CCA) is a rare biliary tract epithelial malignancy. We described the clinical features of CCA patients in our institution. A 10-year retrospective study of patients with cholangiocarcinoma in University Malaya Medical Centre was conducted. Clinical data and outcomes in relation to the three anatomical groups of CCA were collected and analysed. Of the 69 patients that were included 55% were male. Mean age was 61 years. Twelve (17%) had intrahepatic, 38 (55%) perihilar and 19 (28%) distal tumour. Mean age (p=0.043), median duration of symptoms (p=0.011), jaundice (p<0.001), total bilirubin level (p=0.003), INR (p=0.005) and mean tumour size (p=0.048) were significantly related to the site of tumour. Only 12 patients had curative resection with seven R0 resections. Cholangiocarcinoma is increasingly diagnosed in our population. Despite that, the diagnosis is still often late. Age, jaundice and tumour size may predict anatomical location of CCA.
  10. Phyto-synthesis of silver nanoparticles using Alternanthera tenella leaf extract: an effective inhibitor for the migration of human breast adenocarcinoma (MCF-7) cells
    Sathishkumar P, Vennila K, Jayakumar R, Yusoff AR, Hadibarata T, Palvannan T
    Bioprocess Biosyst Eng, 2016 Apr;39(4):651-9.
    PMID: 26801668 DOI: 10.1007/s00449-016-1546-4
    In this study, phyto-synthesis of silver nanoparticles (AgNPs) was achieved using an aqueous leaf extract of Alternanthera tenella. The phytochemical screening results revealed that flavonoids are responsible for the AgNPs formation. The AgNPs were characterised using UV-visible spectrophotometer, field emission scanning microscopy/energy dispersive X-ray, transmission electron microscopy, fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction. The average size of the nanoparticles was found to be ≈48 nm. The EDX results show that strong signals were observed for the silver atoms. The strong band appearing at 1601-1595 cm(-1) correspond to C-C stretching vibration from dienes in FT-IR spectrum indicating the formation of AgNPs. Human breast adenocarcinoma (MCF-7) cells treated with various concentrations of AgNPs showed a dose-dependent increase in cell inhibition. The IC50 value of the AgNPs was calculated to be 42.5 μg mL(-1). The AgNPs showed a significant reduction in the migration of MCF-7 cells.
  11. Methods for the Determination of Endocrine-Disrupting Phthalate Esters
    Qureshi MS, Yusoff AR, Wirzal MD, Sirajuddin, Barek J, Afridi HI, et al.
    Crit Rev Anal Chem, 2016;46(2):146-59.
    PMID: 25831046 DOI: 10.1080/10408347.2015.1004157
    Phthalates are endocrine disruptors frequently occurring in the general and industrial environment and in many industrial products. Moreover, they are also suspected of being carcinogenic, teratogenic, and mutagenic, and they show diverse toxicity profiles depending on their structures. The European Union and the United States Environmental Protection Agency (US EPA) have included many phthalates in the list of priority substances with potential endocrine-disrupting action. They are: dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butylbenzyl phthalate (BBP), diethylhexyl phthalate (DEHP), di-iso-nonyl phthalate (DINP), di-iso-decyl phthalate (DIDP), di-n-decyl phthalate (DnDP), and dioctyl phthalate (DOP). There is an ever-increasing demand for new analytical methods suitable for monitoring different phthalates in various environmental, biological, and other matrices. Separation and spectrometric methods are most frequently used. However, modern electroanalytical methods can also play a useful role in this field because of their high sensitivity, reasonable selectivity, easy automation, and miniaturization, and especially low investment and running costs, which makes them suitable for large-scale monitoring. Therefore, this review outlines possibilities and limitations of various analytical methods for determination of endocrine-disruptor phthalate esters in various matrices, including somewhat neglected electroanalytical methods.
  12. Fulltext Extraneural metastasis of meningeal haemangiopericytoma to the liver
    Yusoff AR, Mokhtar S, Raman K, Singh H, Shabery NAM
    Turk J Gastroenterol, 2019 09;30(9):848-850.
    PMID: 31530530 DOI: 10.5152/tjg.2019.18454
  13. Fulltext Survival analysis of cholangiocarcinoma: a 10-year experience in Malaysia
    Yusoff AR, Razak MM, Yoong BK, Vijeyasingam R, Siti ZM
    World J Gastroenterol, 2012 Feb 7;18(5):458-65.
    PMID: 22346252 DOI: 10.3748/wjg.v18.i5.458
    To investigate the clinical features and survival of patients treated for cholangiocarcinoma in our institution and to analyze the factors affecting their survival.
  14. Pancreatic angiosarcoma: A case report
    Supandi FN, Singh B, Thamutaram H, Lim KF, Yusoff AR
    Ann Hepatobiliary Pancreat Surg, 2021 Jun 30;25(Suppl 1):S388.
    PMID: 34230285 DOI: 10.14701/ahbps.EP-189
    Introduction: Pancreatic cancer has a relative 5-year survival of less than 10%. The most common neoplasm of the pancreas is ductal adenocarcinoma, which comprises 85% of all malignant pancreatic tumours. Primary pancreatic sarcomas are extremely rare which account for less than 0.1% of all pancreatic malignancies and pancreatic angiosarcomas attribute to 1% of all tissue sarcomas. Sarcomas of the pancreas are more aggressive and have a dismal prognosis.

    Methods: A 69-year-old lady presented with obstructive jaundice, abdominal discomfort and associated constitutional symptoms. She was investigated and found to have obstructive jaundice with normal tumor marker assays. An endoscopic ultrasound was done followed by a needle biopsy which confirmed a pancreatic head angiosarcoma followed by an ERCP and a stent placement. A CT abdomen done revealed a pancreatic head and uncinate tumor with a stent in the common bile duct.

    Results: Patient underwent a pylorus preserving pancreaticoduodenectomy with an uneventful post-operative recovery. She defaulted her oncology appointments and was followed up with serial imaging. She developed a local recurrence 18 months after surgery and succumbed to her disease after 3 years.

    Conclusions: Pancreatic angiosarcoma is an aggressive tumor compared to other pancreatic malignancies. For a definite diagnosis of angiosarcoma, histopathologic and immunohistochemical analysis are necessary. Surgical resection offers the only possible cure, while oncological treatment has variable outcome. Currently, there are no treatment protocols available due to the small number of cases present in literature.

  15. Rapid bioremediation of Alizarin Red S and Quinizarine Green SS dyes using Trichoderma lixii F21 mediated by biosorption and enzymatic processes
    Adnan LA, Sathishkumar P, Yusoff AR, Hadibarata T, Ameen F
    Bioprocess Biosyst Eng, 2017 Jan;40(1):85-97.
    PMID: 27663440 DOI: 10.1007/s00449-016-1677-7
    In this study, a newly isolated ascomycete fungus Trichoderma lixii F21 was explored to bioremediate the polar [Alizarin Red S (ARS)] and non-polar [Quinizarine Green SS (QGSS)] anthraquinone dyes. The bioremediation of ARS and QGSS by T. lixii F21 was found to be 77.78 and 98.31 %, respectively, via biosorption and enzymatic processes within 7 days of incubation. The maximum biosorption (ARS = 33.7 % and QGSS = 74.7 %) and enzymatic biodegradation (ARS = 44.1 % and QGSS = 23.6 %) were observed at pH 4 and 27 °C in the presence of glucose and yeast extract. The laccase and catechol 1,2-dioxygenase produced by T. lixii F21 were involved in the molecular conversions of ARS and QGSS to phenolic and carboxylic acid compounds, without the formation of toxic aromatic amines. This study suggests that T. lixii F21 may be a good candidate for the bioremediation of industrial effluents contaminated with anthraquinone dyes.
  16. Fulltext Bandgap tuning of mixed organic cation utilizing chemical vapor deposition process
    Kim J, Kim HP, Teridi MA, Yusoff AR, Jang J
    Sci Rep, 2016 11 22;6:37378.
    PMID: 27874026 DOI: 10.1038/srep37378
    Bandgap tuning of a mixed organic cation perovskite is demonstrated via chemical vapor deposition process. The optical and electrical properties of the mixed organic cation perovskite can be manipulated by varying the growth time. A slight shift of the absorption band to shorter wavelengths is demonstrated with increasing growth time, which results in the increment of the current density. Hence, based on the optimized growth time, our device exhibits an efficiency of 15.86% with negligible current hysteresis.
  17. Anti-acne, anti-dandruff and anti-breast cancer efficacy of green synthesised silver nanoparticles using Coriandrum sativum leaf extract
    Sathishkumar P, Preethi J, Vijayan R, Mohd Yusoff AR, Ameen F, Suresh S, et al.
    J. Photochem. Photobiol. B, Biol., 2016 Oct;163:69-76.
    PMID: 27541567 DOI: 10.1016/j.jphotobiol.2016.08.005
    In this present investigation, AgNPs were green synthesised using Coriandrum sativum leaf extract. The physicochemical properties of AgNPs were characterised using UV-visible spectrophotometer, field emission scanning microscopy/energy dispersive X-ray (FESEM/EDX), Fourier transformed infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analysis. Further, in vitro anti-acne, anti-dandruff and anti-breast cancer efficacy of green synthesised AgNPs were assessed against Propionibacterium acnes MTCC 1951, Malassezia furfur MTCC 1374 and human breast adenocarcinoma (MCF-7) cell line, respectively. The flavonoids present in the plant extract were responsible for the AgNPs synthesis. The green synthesised nanoparticles size was found to be ≈37nm. The BET analysis result shows that the surface area of the synthesised AgNPs was found to be 33.72m(2)g(-1). The minimal inhibitory concentration (MIC) of AgNPs for acne causative agent P. acnes and dandruff causative agent M. furfur was found to be at 3.1 and 25μgmL(-1), respectively. The half maximal inhibitory concentration (IC50) value of the AgNPs for MCF-7 cells was calculated as 30.5μgmL(-1) and complete inhibition was observed at a concentration of 100μgmL(-1). Finally, our results proved that green synthesised AgNPs using C. sativum have great potential in biomedical applications such as anti-acne, anti-dandruff and anti-breast cancer treatment.
  18. Electrospun nylon 6,6 membrane as a reusable nano-adsorbent for bisphenol A removal: Adsorption performance and mechanism
    Jasni MJF, Arulkumar M, Sathishkumar P, Mohd Yusoff AR, Buang NA, Gu FL
    J Colloid Interface Sci, 2017 Dec 15;508:591-602.
    PMID: 28869916 DOI: 10.1016/j.jcis.2017.08.075
    Bisphenol A (BPA) is highly considered as an emerging contaminants (ECs) due to their endocrine disrupting and reproductive toxicant nature. It has been detected in drinking water sources in many countries. This study deals with the adsorptive removal of BPA using nylon 6,6 nanofibrous membrane (NNM) fabricated by electrospinning technique. Langmuir and Freundlich isotherm models (R2=0.99) were obeyed for BPA adsorption, which indicates the monolayer adsorption of BPA and also surface heterogeneity of NNM. The adsorption kinetics of BPA was followed pseudo second order rate (R2=0.89-0.99), which suggests the occurrence of rapid adsorption rate through interaction of surface functional groups present in NNM. The maximum adsorption of BPA (91.3mgg-1) was attained at 30°C. The hydroxyl groups of BPA form hydrogen bonding with carbonyl groups of NNM during the adsorptive removal process. Reusability study confirmed a much better stability of NNM in the recyclic application. Finally, this study suggests that NNM might be an outstanding nano-adsorbent for the emerging contaminants removal, including BPA from drinking water sources.
  19. Fulltext Stable and null current hysteresis perovskite solar cells based nitrogen doped graphene oxide nanoribbons hole transport layer
    Kim J, Mat Teridi MA, Mohd Yusoff AR, Jang J
    Sci Rep, 2016 06 09;6:27773.
    PMID: 27277388 DOI: 10.1038/srep27773
    Perovskite solar cells are becoming one of the leading technologies to reduce our dependency on traditional power sources. However, the frequently used component poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (

    PEDOT: PSS) has several shortcomings, such as an easily corroded indium-tin-oxide (ITO) interface at elevated temperatures and induced electrical inhomogeneity. Herein, we propose solution-processed nitrogen-doped graphene oxide nanoribbons (NGONRs) as a hole transport layer (HTL) in perovskite solar cells, replacing the conducting polymer

    PEDOT: PSS. The conversion efficiency of NGONR-based perovskite solar cells has outperformed a control device constructed using

    PEDOT: PSS. Moreover, our proposed NGONR-based devices also demonstrate a negligible current hysteresis along with improved stability. This work provides an effective route for substituting

    PEDOT: PSS as the effective HTL.

  20. PVDF-ErGO-GRC electrode: A single setup electrochemical system for separation, pre-concentration and detection of lead ions in complex aqueous samples
    Hamsawahini K, Sathishkumar P, Ahamad R, Yusoff AR
    Talanta, 2016 Feb 1;148:101-7.
    PMID: 26653429 DOI: 10.1016/j.talanta.2015.10.044
    An effective electrode was developed based on electromembrane extraction (EME) and square wave voltammetry (SWV) for simultaneous separation, pre-concentration and determination of lead (II) (Pb(II)) ions in complex aqueous samples. Electrochemically reduced graphene oxide-graphite reinforced carbon (ErGO-GRC) was utilized in conjunction with the SWV. Pb(II) ions were extracted from an aqueous sample solution into an acidic acceptor phase (1M HCl) in the lumen of the polyvinylidene fluoride (PVDF) membrane bag by the application of voltage of maximum 6 V across the supported liquid membrane (SLM), consisting of organic solvent and di-(2-ethylhexyl)phosphoric acid (D2EHPA). The parameters affecting the EME were optimized for Pb(II) ions. The optimum EME conditions were found to be 20% D2EHPA in 1-octanol impregnated in the wall of PVDF membrane (PVDF17) as the SLM, extraction time of 20 min, pH of sample solution of 8 and a voltage of 5 V. The PVDF-ErGO-GRC electrode system attained enrichment factors of 40 times and 80% of extraction with relative standard deviations (n=5) of 8.3%. Good linearity ranging from 0.25 to 2 nM with coefficients correlation of 0.999 was obtained. The Pb(II) ions detection limit of PVDF-ErGO-GRC electrode was found to be 0.09 nM. The newly developed single setup electrochemical system was applied to complex aqueous samples such as tap, river and sea water to evaluate the feasibility of the method for applications.
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