Displaying publications 1 - 20 of 34 in total

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  1. Hussain Z, Khan S, Imran M, Sohail M, Shah SWA, de Matas M
    Drug Deliv Transl Res, 2019 06;9(3):721-734.
    PMID: 30895453 DOI: 10.1007/s13346-019-00631-4
    On account of heterogeneity, intrinsic ability of drug resistance, and the potential to invade to other parts of the body (malignancy), the development of a rational anticancer regimen is dynamically challenging. Chemotherapy is considered the gold standard for eradication of malignancy and mitigation of its reoccurrence; nevertheless, it has also been associated with detrimental effects to normal tissues owing to its nonselectivity and nominal penetration into the tumor tissues. In recent decades, nanotechnology-guided interventions have been well-acclaimed due to their ability to facilitate target-specific delivery of drugs, avoidance of nontarget distribution, alleviated systemic toxicity, and maximized drug internalization into cancer cells. Despite their numerous biomedical advantages, clinical translation of nanotechnology-mediated regimens is challenging due to their short plasma half-life and early clearance. PEGylation of nanomedicines has been adapted as an efficient strategy to extend plasma half-life and diminished early plasma clearance via alleviating the opsonization (uptake by monocytes and macrophages) of drug nanocarriers. PEGylation provides "stealth" properties to nanocarrier's surfaces which diminished their recognition or uptake by cellular immune system, leading to longer circulation time, reduced dosage and frequency, and superior site-selective delivery of drugs. Therefore, this review aims to present a comprehensive overview of the pharmaceutical advantages and therapeutic feasibility of PEGylation of nanocarriers in improving tumor-specific targetability, reversing drug resistance, and improving pharmacokinetic profile of drugs and anticancer efficacy. Challenges to PEGylated cancer nanomedicines, possible adaptations to resolve those challenges, and pivotal requirement for interdisciplinary research for development of rational anticancer regimen have also been pondered.
  2. Sohail M, Mudassir, Minhas MU, Khan S, Hussain Z, de Matas M, et al.
    Drug Deliv Transl Res, 2019 04;9(2):595-614.
    PMID: 29611113 DOI: 10.1007/s13346-018-0512-x
    Ulcerative colitis (UC) is an inflammatory disease of the colon that severely affects the quality of life of patients and usually responds well to anti-inflammatory agents for symptomatic relief; however, many patients need colectomy, a surgical procedure to remove whole or part of the colon. Though various types of pharmacological agents have been employed for the management of UC, the lack of effectiveness is usually predisposed to various reasons including lack of target-specific delivery of drugs and insufficient drug accumulation at the target site. To overcome these glitches, many researchers have designed and characterized various types of versatile polymeric biomaterials to achieve target-specific delivery of drugs via oral route to optimize their targeting efficiency to the colon, to improve drug accumulation at the target site, as well as to ameliorate off-target effects of chemotherapy. Therefore, the aim of this review was to summarize and critically discuss the pharmaceutical significance and therapeutic feasibility of a wide range of natural and synthetic biomaterials for efficient drug targeting to colon and rationalized treatment of UC. Among various types of biomaterials, natural and synthetic polymer-based hydrogels have shown promising targeting potential due to their innate pH responsiveness, sustained and controlled release characteristics, and microbial degradation in the colon to release the encapsulated drug moieties. These characteristic features make natural and synthetic polymer-based hydrogels superior to conventional pharmacological strategies for the management of UC.
  3. Khan MA, Khan S, Kazi M, Alshehri SM, Shahid M, Khan SU, et al.
    Pharmaceutics, 2021 Oct 06;13(10).
    PMID: 34683925 DOI: 10.3390/pharmaceutics13101632
    Norfloxacin (NOR), widely employed as an anti-bacterial drug, has poor oral bioavailability. Nano based drug delivery systems are widely used to overcome the existing oral bioavailability challenges. Lipid-Polymer Hybrid Nanoparticles (LPHNs) exhibit the distinctive advantages of both polymeric and liposomes nanoparticles, while excluding some of their disadvantages. In the current study, NOR loaded LPHNs were prepared, and were solid amorphous in nature, followed by in vitro and in vivo evaluation. The optimized process conditions resulted in LPHNs with the acceptable particle size 121.27 nm, Polydispersity Index (PDI) of 0.214 and zeta potential of -32 mv. The addition of a helper lipid, oleic acid, and polymers, ethyl cellulose, substantially increased the encapsulation efficiency (EE%) (65% to 97%). In vitro study showed a sustained drug release profile (75% within 12 h) for NOR LPHNs. The optimized NOR LPHNs showed a significant increase (p < 0.05) in bioavailability compared to the commercial product. From the acute toxicity study, the LD50 value was found to be greater than 1600 mg/kg. The molecular modelling studies substantiated the experimental results with the best combination of polymers and surfactants that produced highly stable LPHNs. Therefore, LPHNs proved to be a promising system for the delivery of NOR, as well as for other antibiotics and hydrophobic drugs.
  4. Rahim MA, Jan N, Khan S, Shah H, Madni A, Khan A, et al.
    Cancers (Basel), 2021 Feb 07;13(4).
    PMID: 33562376 DOI: 10.3390/cancers13040670
    The tumor-specific targeting of chemotherapeutic agents for specific necrosis of cancer cells without affecting the normal cells poses a great challenge for researchers and scientists. Though extensive research has been carried out to investigate chemotherapy-based targeted drug delivery, the identification of the most promising strategy capable of bypassing non-specific cytotoxicity is still a major concern. Recent advancements in the arena of onco-targeted therapies have enabled safe and effective tumor-specific localization through stimuli-responsive drug delivery systems. Owing to their promising characteristic features, stimuli-responsive drug delivery platforms have revolutionized the chemotherapy-based treatments with added benefits of enhanced bioavailability and selective cytotoxicity of cancer cells compared to the conventional modalities. The insensitivity of stimuli-responsive drug delivery platforms when exposed to normal cells prevents the release of cytotoxic drugs into the normal cells and therefore alleviates the off-target events associated with chemotherapy. Contrastingly, they showed amplified sensitivity and triggered release of chemotherapeutic payload when internalized into the tumor microenvironment causing maximum cytotoxic responses and the induction of cancer cell necrosis. This review focuses on the physical stimuli-responsive drug delivery systems and chemical stimuli-responsive drug delivery systems for triggered cancer chemotherapy through active and/or passive targeting. Moreover, the review also provided a brief insight into the molecular dynamic simulations associated with stimuli-based tumor targeting.
  5. Siow SL, Wong CM, Sohail M
    Med J Malaysia, 2009 Jun;64(2):168-9.
    PMID: 20058581 MyJurnal
    Gastric outlet obstruction and in particular, pyloric stenosis, is relatively common in developing countries. Acute clinical presentation is often the manifestation of biochemical and electrolyte changes. The presence of metabolic alkalosis in combination with acute renal failure should alarm us to the possibility of adult pyloric stenosis. We report a case of adult pyloric stenosis that presented as acute renal failure and discuss its pathophysiology.
  6. Siow SL, Wong CM, Hardin M, Sohail M
    J Med Case Rep, 2016 Jan 18;10:11.
    PMID: 26781191 DOI: 10.1186/s13256-015-0780-8
    Traumatic diaphragmatic rupture and traumatic abdominal wall hernia are two well-described but rare clinical entities associated with blunt thoracoabdominal injuries. To the best of our knowledge, the combination of these two clinical entities as a result of a motor vehicle accident has not been previously reported.
  7. Sim SK, Myo N, Sohail M
    Med J Malaysia, 2023 Jan;78(1):61-67.
    PMID: 36715193
    INTRODUCTION: To evaluate the effectiveness of team-based self-directed learning (SDL) in the teaching of the undergraduate Year 5 surgical posting.

    MATERIALS AND METHODS: A quasi-experimental study was conducted to develop and administer a team-based SDL versus a conventional SDL to teach undergraduate surgical topics. One hundred and seventy-four medical students who underwent the Year 5 surgical posting were recruited. They were assigned to two groups receiving either the teambased SDL or the conventional SDL. Pre- and post-SDL assessments were conducted to determine students' understanding of selected surgical topics. A selfadministered questionnaire was used to collect student feedback on the team-based SDL.

    RESULTS: The team-based SDL group scored significantly higher than the conventional SDL group in the post-SDL assessment (74.70 ± 6.81 vs. 63.77 ± 4.18, t = -12.72, p < 0.01). The students agreed that the team-based SDL method facilitated their learning process.

    CONCLUSION: The study demonstrated that the use of a teambased SDL is an effective learning strategy for teaching the Year 5 surgical posting. This method encouraged peer discussion and promoted teamwork in completing task assignments to achieve the learning objectives.

  8. Amin F, Khan S, Shah SMH, Rahim H, Hussain Z, Sohail M, et al.
    Drug Des Devel Ther, 2018;12:3855-3866.
    PMID: 30510401 DOI: 10.2147/DDDT.S183534
    Background: The obnoxious bitter taste of orally taken antibiotics is one of the biggest problems in the treatment of children. The pediatric population cannot tolerate the bitter taste of drugs and vomit out which ultimately leads to suboptimal therapeutic value, grimace and mental stress so it is the challenging task for the formulation scientists to formulate a palatable formulation particularly to overcome address the issue.

    Purpose of study: The study aimed to mask and evaluate the unpleasant bitter taste of azithro-mycin (AZ) in the dry suspension dosage form by physisorption technique.

    Materials and methods: AZ was selected as an adsorbent and titanium dioxide nanoparticles as adsorbate. The AZ nanohybrids (AZN) were prepared by treating fixed amount of adsorbent with a varied amount of adsorbate, prepared separately by dispersing it in an aqueous medium. The mixture was sonicated, stirred followed by filtration and drying. The AZN produced were characterized by various techniques including scanning electron microscopy (SEM), energy dispersive X-rays (EDX), powder X-ray diffraction (PXRD), HPLC and Fourier-transformed infrared (FTIR). The optimized nanohybrid was blended with other excipients to get stable and taste masked dry suspension dosage form.

    Results: The results confirmed the adsorption of titanium dioxide nanoparticles on the surface of AZ. The fabricated optimized formulation was subjected for taste masking by panel testing and accelerated stability studies. The results showed a remarkable improvement in bitter taste masking, inhibiting throat bite without affecting the dissolution rate. The product showed an excellent stability both in dry and reconstituted suspension. The optimized formulation of AZN and was found stable when subjected to physical and chemical stability studies, this is because of short and single step process which interns limits the exposure of the product to various environmental factors that could potentially affect the stability of the product. The dissolution rate of the optimized formulation of AZN was compared with its marketed counterpart, showing the same dissolution rate compared to its marketed formulation.

    Conclusion: The current study concludes that, by fabricating AZ-titanium nanohybrids using physisorption can effectively mask the bitter taste of the drug. The palatability and stability of azithromycin formulation was potentially enhanced without affecting its dissolution rate.

  9. Moti LAA, Hussain Z, Thu HE, Khan S, Sohail M, Sarfraz RM
    Curr Pharm Des, 2021;27(43):4356-4375.
    PMID: 34459374 DOI: 10.2174/1381612827666210830092539
    BACKGROUND: Breast cancer (BC) is one of the most aggressive and prevalent types of cancer, which is associated with a high rate of mortality and colossal potential of metastasis to other body organs. Conventionally, there are three commonly employed strategies for the treatment of BC including, surgery, radiations and chemotherapy; however, these modalities are associated with several deleterious effects and a high rate of relapse.

    OBJECTIVE: This review was aimed to critically discuss and conceptualize existing evidences related to the pharmaceutical significance and therapeutic feasibility of multi-functionalization of nanomedicines for early diagnosis and efficient treatment of BC.

    RESULTS: Though the implication of nanotechnology-based modalities has revolutionised the outcomes of diagnosis and treatment of BC; however, the clinical translation of these nanomedicines is facing grandeur challenges. These challenges include recognition by the reticuloendothelial system (RES), short plasma half-life, non-specific accumulation in the non-cancerous cells, and expulsion of the drug(s) by the efflux pump. To circumvent these challenges, various adaptations such as PEGylation, conjugation of targeting ligand(s), and siteresponsive behaviour (i.e., pH-responsiveness, biochemical, or thermal-responsiveness) have been adapted. Similarly, multi-functionalization of nanomedicines has emerged as an exceptional strategy to improve the pharmacokinetic profile, specific targetability to the tumor microenvironment (active targeting) and efficient internalization, and to alleviate the expulsion of internalized drug contents by silencing-off efflux pump.

    CONCLUSION: Critical analysis of the available evidences revealed that multi-functionalization of nanomedicines is a plausible and sustainable adaptation for early diagnosis and treatment of BC with better therapeutic outcomes.

  10. Ahmad U, Sohail M, Ahmad M, Minhas MU, Khan S, Hussain Z, et al.
    Int J Biol Macromol, 2019 May 15;129:233-245.
    PMID: 30738157 DOI: 10.1016/j.ijbiomac.2019.02.031
    Oral drug delivery is natural, most acceptable and desirable route for nearly all drugs, but many drugs like NSAIDs when delivered by this route cause gastrointestinal irritation, gastric bleeding, ulcers, and many undesirable effects which limits their usage by oral delivery. Moreover, it is almost impossible to control the release of a drug in a targeted location in body. We developed thermo-responsive chitosan-co-poly(N-isopropyl-acrylamide) injectable hydrogel as an alternative for the gastro-protective and controlled delivery of loxoprofen sodium as a model drug. A free radical polymerization technique was used to synthesize thermo-responsive hydrogel by cross-linking chitosan HCl with NIPAAM using glutaraldehyde as cross-linker. Confirmation of crosslinked hydrogel structure was done by Fourier transform infrared spectra (FTIR). The thermal stability of hydrogel was confirmed through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The scanning electron microscopy (SEM) was performed to evaluate the structural morphology of cross-linked hydrogel. To evaluate the rheological behavior of hydrogel with increasing temperature, rheological study was performed. Swelling and in vitro drug release studies were carried out under various temperature and pH conditions. The swelling study revealed that maximum swelling was observed at low pH (pH 1.2) and low temperature (25 °C) compared to the high range of pH and temperature and it resulted in quick release of the drug. The high range of pH (7.4) and temperature (37 °C) however caused controlled release of the drug. The in vivo evaluation of the developed hydrogel in rabbits demonstrated the controlled release behavior of fabricated system.
  11. Shoaib Ahmad Shah S, Altaf Nazir M, Mahmood A, Sohail M, Ur Rehman A, Khurram Tufail M, et al.
    Chem Rec, 2024 Jan;24(1):e202300141.
    PMID: 37724006 DOI: 10.1002/tcr.202300141
    Electrical conductivity is very important property of nanomaterials for using wide range of applications especially energy applications. Metal-organic frameworks (MOFs) are notorious for their low electrical conductivity and less considered for usage in pristine forms. However, the advantages of high surface area, porosity and confined catalytic active sites motivated researchers to improve the conductivity of MOFs. Therefore, 2D electrical conductive MOFs (ECMOF) have been widely synthesized by developing the effective synthetic strategies. In this article, we have summarized the recent trends in developing the 2D ECMOFs, following the summary of potential applications in the various fields with future perspectives.
  12. Hayat A, Sohail M, Ali H, Taha TA, Qazi HIA, Ur Rahman N, et al.
    Chem Rec, 2022 Nov 21.
    PMID: 36408911 DOI: 10.1002/tcr.202200149
    Recently, the growing demand for a renewable and sustainable fuel alternative is contingent on fuel cell technologies. Even though it is regarded as an environmentally sustainable method of generating fuel for immediate concerns, it must be enhanced to make it extraordinarily affordable, and environmentally sustainable. Hydrogen (H2 ) synthesis by electrochemical water splitting (ECWS) is considered one of the foremost potential prospective methods for renewable energy output and H2 society implementation. Existing massive H2 output is mostly reliant on the steaming reformation of carbon fuels that yield CO2 together with H2 and is a finite resource. ECWS is a viable, efficient, and contamination-free method for H2 evolution. Consequently, developing reliable and cost-effective technology for ECWS was a top priority for scientists around the globe. Utilizing renewable technologies to decrease total fuel utilization is crucial for H2 evolution. Capturing and transforming the fuel from the ambient through various renewable solutions for water splitting (WS) could effectively reduce the need for additional electricity. ECWS is among the foremost potential prospective methods for renewable energy output and the achievement of a H2 -based economy. For the overall water splitting (OWS), several transition-metal-based polyfunctional metal catalysts for both cathode and anode have been synthesized. Furthermore, the essential to the widespread adoption of such technology is the development of reduced-price, super functional electrocatalysts to substitute those, depending on metals. Many metal-premised electrocatalysts for both the anode and cathode have been designed for the WS process. The attributes of H2 and oxygen (O2 ) dynamics interactions on the electrodes of water electrolysis cells and the fundamental techniques for evaluating the achievement of electrocatalysts are outlined in this paper. Special emphasis is paid to their fabrication, electrocatalytic performance, durability, and measures for enhancing their efficiency. In addition, prospective ideas on metal-based WS electrocatalysts based on existing problems are presented. It is anticipated that this review will offer a straight direction toward the engineering and construction of novel polyfunctional electrocatalysts encompassing superior efficiency in a suitable WS technique.
  13. Hayat A, Sohail M, Anwar U, Taha TA, Qazi HIA, Amina, et al.
    Chem Rec, 2023 Jan;23(1):e202200143.
    PMID: 36285706 DOI: 10.1002/tcr.202200143
    The increasing demand for searching highly efficient and robust technologies in the context of sustainable energy production totally rely onto the cost-effective energy efficient production technologies. Solar power technology in this regard will perceived to be extensively employed in a variety of ways in the future ahead, in terms of the combustion of petroleum-based pollutants, CO2 reduction, heterogeneous photocatalysis, as well as the formation of unlimited and sustainable hydrogen gas production. Semiconductor-based photocatalysis is regarded as potentially sustainable solution in this context. g-C3 N4 is classified as non-metallic semiconductor to overcome this energy demand and enviromental challenges, because of its superior electronic configuration, which has a median band energy of around 2.7 eV, strong photocatalytic stability, and higher light performance. The photocatalytic performance of g-C3 N4 is perceived to be inadequate, owing to its small surface area along with high rate of charge recombination. However, various synthetic strategies were applied in order to incorporate g-C3 N4 with different guest materials to increase photocatalytic performance. After these fabrication approaches, the photocatalytic activity was enhanced owing to generation of photoinduced electrons and holes, by improving light absorption ability, and boosting surface area, which provides more space for photocatalytic reaction. In this review, various metals, non-metals, metals oxide, sulfides, and ferrites have been integrated with g-C3 N4 to form mono, bimetallic, heterojunction, Z-scheme, and S-scheme-based materials for boosting performance. Also, different varieties of g-C3 N4 were utilized for different aspects of photocatalytic application i. e., water reduction, water oxidation, CO2 reduction, and photodegradation of dye pollutants, etc. As a consequence, we have assembled a summary of the latest g-C3 N4 based materials, their uses in solar energy adaption, and proper management of the environment. This research will further well explain the detail of the mechanism of all these photocatalytic processes for the next steps, as well as the age number of new insights in order to overcome the current challenges.
  14. Sohail M, Alyson T, Sim SK, Nik Azim NA
    Med J Malaysia, 2020 09;75(5):606-608.
    PMID: 32918439
    Ileo-ileal knotting is a rare cause of intestinal obstruction. In this condition, one bowel loop makes a knot with an adjacent bowel loop, resulting in mechanical obstruction and even gangrene of the bowel. We present a case of a young girl with ileo-ileal knotting resulting in a closed-loop obstruction and gangrene of the small bowel loop. This is a difficult condition to diagnose; a high index of suspicion and early surgical intervention are essential to reduce morbidity and mortality.
  15. Sohail M, Loke SN, Sim SK, Nik Azim NA
    Med J Malaysia, 2021 05;76(3):432-435.
    PMID: 34031348
    We present here a case of a 66-year-old lady who was diagnosed with right iliac fossa retroperitoneal leiomyosarcoma at Hospital Umum Sarawak. The challenge in this case was the extension of tumour with the involvement of her right ureter causing proximal hydroureter and hydronephrosis. After resection of tumour en-block with the involved segment of ureter, it was not possible to repair the ureteric defect directly. We used interpositional vascularized appendix graft to repair this large (7 cm) ureteric defect. We describe here this uncommon technique of ureter reconstruction.
  16. Sohail M, Chua RHB, Sim SK, Nik Azim NA
    Med J Malaysia, 2022 Jan;77(1):125-127.
    PMID: 35087013
    A 60-year-old lady presented with lower abdominal discomfort and a huge palpable intra-abdominal mass for 4 months, with significant weight loss over half a year. Transvaginal ultrasonography and computed tomography (CT) abdomen showed a large right solid cystic mass likely ovarian in origin. The CA-125 was raised. With the provisional diagnosis of ovarian cancer patient underwent laparotomy at Hospital Umum Sarawak, Malaysia. However intraoperative findings showed that uterus and both ovaries were normal. The tumour was arising from the jejunum and adherent to the dome of the urinary bladder and right broad ligament. The tumour was resected and final diagnosis was jejunal gastrointestinal stromal tumour (GIST). We described this case which was misinterpreted as an ovarian cancer.
  17. Sohail M, Altalhi T, Al-Sehemi AG, Taha TAM, S El-Nasser K, Al-Ghamdi AA, et al.
    Nanomaterials (Basel), 2021 Nov 29;11(12).
    PMID: 34947595 DOI: 10.3390/nano11123245
    Light-driven heterogeneous photocatalysis has gained great significance for generating solar fuel; the challenging charge separation process and sluggish surface catalytic reactions significantly restrict the progress of solar energy conversion using a semiconductor photocatalyst. Herein, we propose a novel and feasible strategy to incorporate dihydroxy benzene (DHB) as a conjugated monomer within the framework of urea containing CN (CNU-DHBx) to tune the electronic conductivity and charge separation due to the aromaticity of the benzene ring, which acts as an electron-donating species. Systematic characterizations such as SPV, PL, XPS, DRS, and TRPL demonstrated that the incorporation of the DHB monomer greatly enhanced the photocatalytic CO2 reduction of CN due to the enhanced charge separation and modulation of the ionic mobility. The significantly enhanced photocatalytic activity of CNU-DHB15.0 in comparison with parental CN was 85 µmol/h for CO and 19.92 µmol/h of the H2 source. It can be attributed to the electron-hole pair separation and enhance the optical adsorption due to the presence of DHB. Furthermore, this remarkable modification affected the chemical composition, bandgap, and surface area, encouraging the controlled detachment of light-produced photons and making it the ideal choice for CO2 photoreduction. Our research findings potentially offer a solution for tuning complex charge separation and catalytic reactions in photocatalysis that could practically lead to the generation of artificial photocatalysts for efficient solar energy into chemical energy conversion.
  18. Hayat A, Sohail M, Ali Shah Syed J, Al-Sehemi AG, Mohammed MH, Al-Ghamdi AA, et al.
    Chem Rec, 2022 Feb 09.
    PMID: 35138017 DOI: 10.1002/tcr.202100310
    Being one of the foremost enticing and intriguing innovations, heterogeneous photocatalysis has also been used to effectively gather, transform, and conserve sustainable sun's radiation for the production of efficient and clean fossil energy as well as a wide range of ecological implications. The generation of solar fuel-based water splitting and CO2 photoreduction is excellent for generating alternative resources and reducing global warming. Developing an inexpensive photocatalyst can effectively split water into hydrogen (H2 ), oxygen (O2 ) sources, and carbon dioxide (CO2 ) into fuel sources, which is a crucial problem in photocatalysis. The metal-free g-C3 N4 photocatalyst has a high solar fuel generation potential. This review covers the most recent advancements in g-C3 N4 preparation, including innovative design concepts and new synthesis methods, and novel ideas for expanding the light absorption of pure g-C3 N4 for photocatalytic application. Similarly, the main issue concerning research and prospects in photocatalysts based g-C3 N4 was also discussed. The current dissertation provides an overview of comprehensive understanding of the exploitation of the extraordinary systemic and characteristics, as well as the fabrication processes and uses of g-C3 N4 .
  19. Ehsan MA, Naeem R, Khaledi H, Sohail M, Hakeem Saeed A, Mazhar M
    Dalton Trans, 2016 Jun 21;45(25):10222-32.
    PMID: 27230711 DOI: 10.1039/c6dt01016d
    Cobalt titanate-titania composite oxide films have been grown on FTO-coated glass substrates using a single-source heterometallic complex [Co2Ti4(μ-O)6(TFA)8(THF)6]·THF () which was obtained in quantitative yield from the reaction of diacetatocobalt(ii) tetrahydrate, tetraisopropoxytitanium(iv), and trifluoroacetic acid from a tetrahydrofuran solution. Physicochemical investigations of complex have been carried out by melting point, FT-IR, thermogravimetric and single-crystal X-ray diffraction analyses. CoTiO3-TiO2 films composed of spherical objects of various sizes have been grown from by aerosol-assisted chemical vapor deposition at different temperatures of 500, 550 and 600 °C. Thin films characterized by XRD, Raman and X-ray photoelectron spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis have been explored for electrochemical detection of dopamine (DA). The cyclic voltammetry with the CoTiO3-TiO2 electrode showed a DA oxidation peak at +0.215 V while linear sweep voltammetry displayed a detection limit (LoD) of 0.083 μM and a linear concentration range of 20-300 μM for DA. Thus, the CoTiO3-TiO2 electrode is a potential candidate for the sensitive and selective detection of DA.
  20. Naeem R, Ali Ehsan M, Yahya R, Sohail M, Khaledi H, Mazhar M
    Dalton Trans, 2016 Oct 14;45(38):14928-39.
    PMID: 27549401 DOI: 10.1039/c6dt02656g
    Pristine Mn2O3 and Ag-Mn2O3 composite thin films have been developed on fluorine doped tin oxide (FTO) coated glass substrates at 450 °C by aerosol assisted chemical vapor deposition (AACVD) using a methanol solution of a 1 : 2 mixture of acetatoargentate(i), Ag(CH3COO), and a newly synthesized manganese complex, [Mn(dmae)2(TFA)4] (1) (dmae = N,N-dimethylaminoethanolate, TFA = trifluoroacetate). The phase purity and stoichiometric composition of the films were investigated by X-ray diffraction (XRD) and Raman spectroscopy techniques. Energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) analyses revealed a Ag to Mn ratio of 1 : 2 and further confirmed the uniform dispersion of Ag nanoparticles into the Mn2O3 structure. Optical studies showed a direct band gap of 2.0 eV for the pristine Mn2O3 film that was lowered to 1.8 eV for Ag-Mn2O3 due to the plasmonic interaction of Ag with Mn2O3. The Ag-Mn2O3 composite film displayed enhanced photocatalytic activity in photoelectrochemical (PEC) water splitting and yielded a photocurrent of 3 mA cm(-2) at 0.7 V versus Ag/AgCl which was 1.6 times higher than a pristine Mn2O3 film alone, under AM 1.5 G illumination (100 mW cm(-2)). The high PEC efficiency is mainly due to the plasmonic effect of Ag nanoparticles, which enhances the visible light absorption, efficient electron-hole separation and high carrier mobility of the Ag-Mn2O3 photoelectrode. The charge carrier density of Ag-Mn2O3 is two times higher than the pristine Mn2O3 as calculated by the Mott-Schottky plot. Based on the PEC studies a mechanism is proposed to elucidate the high activity of Ag-Mn2O3 in PEC water splitting.
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