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Fulltext Optimization of the Synthesis of Superhydrophobic Carbon Nanomaterials by Chemical Vapor Deposition

Aljumaily MM, Alsaadi MA, Das R, Hamid SBA, Hashim NA, AlOmar MK, et al.

Sci Rep, 2018 02 09;8(1):2778.
PMID: 29426860 DOI: 10.1038/s41598-018-21051-3

Demand is increasing for superhydrophobic materials in many applications, such as membrane distillation, separation and special coating technologies. In this study, we report a chemical vapor deposition (CVD) process to fabricate superhydrophobic carbon nanomaterials (CNM) on nickel (Ni)-doped powder activated carbon (PAC). The reaction temperature, reaction time and H2/C2H2 gas ratio were optimized to achieve the optimum contact angle (CA) and carbon yield (CY). For the highest CY (380%) and CA (177°), the optimal reaction temperatures were 702 °C and 687 °C, respectively. However, both the reaction time (40 min) and gas ratio (1.0) were found to have similar effects on CY and CA. Based on the Field emission scanning electron microscopy and transmission electron microscopy images, the CNM could be categorized into two main groups: a) carbon spheres (CS) free carbon nanofibers (CNFs) and b) CS mixed with CNFs, which were formed at 650 and 750 °C, respectively. Raman spectroscopy and thermogravimetric analysis also support this finding. The hydrophobicity of the CNM, expressed by the CA, follows the trend of CS-mixed CNFs (CA: 177°) > CS-free CNFs (CA: 167°) > PAC/Ni (CA: 65°). This paves the way for future applications of synthesized CNM to fabricate water-repellent industrial-grade technologies.

Matched MeSH terms: Spectrum Analysis, Raman
Fulltext Graphene Oxide as a Nanocarrier for a Theranostics Delivery System of Protocatechuic Acid and Gadolinium/Gold Nanoparticles

Usman MS, Hussein MZ, Kura AU, Fakurazi S, Masarudin MJ, Ahmad Saad FF

Molecules, 2018 Feb 24;23(2).
PMID: 29495251 DOI: 10.3390/molecules23020500

We have synthesized a graphene oxide (GO)-based theranostic nanodelivery system (GOTS) for magnetic resonance imaging (MRI) using naturally occurring protocatechuic acid (PA) as an anticancer agent and gadolinium (III) nitrate hexahydrate (Gd) as the starting material for a contrast agent,. Gold nanoparticles (AuNPs) were subsequently used as second diagnostic agent. The GO nanosheets were first prepared from graphite via the improved Hummer's protocol. The conjugation of the GO and the PA was done via hydrogen bonding and π-π stacking interactions, followed by surface adsorption of the AuNPs through electrostatic interactions. GAGPA is the name given to the nanocomposite obtained from Gd and PA conjugation. However, after coating with AuNPs, the name was modified to GAGPAu. The physicochemical properties of the GAGPA and GAGPAu nanohybrids were studied using various characterization techniques. The results from the analyses confirmed the formation of the GOTS. The powder X-ray diffraction (PXRD) results showed the diffractive patterns for pure GO nanolayers, which changed after subsequent conjugation of the Gd and PA. The AuNPs patterns were also recorded after surface adsorption. Cytotoxicity and magnetic resonance imaging (MRI) contrast tests were also carried out on the developed GOTS. The GAGPAu was significantly cytotoxic to the human liver hepatocellular carcinoma cell line (HepG2) but nontoxic to the standard fibroblast cell line (3T3). The GAGPAu also appeared to possess higher T1 contrast compared to the pure Gd and water reference. The GOTS has good prospects of serving as future theranostic platform for cancer chemotherapy and diagnosis.

Matched MeSH terms: Spectrum Analysis, Raman
Synthesis of carbon-based quantum dots from starch extracts: Optical investigations

Al-Douri Y, Badi N, Voon CH

Luminescence, 2018 Mar;33(2):260-266.
PMID: 29024360 DOI: 10.1002/bio.3408

Carbon-based quantum dots (C-QDs) were synthesized through microwave-assisted carbonization of an aqueous starch suspension mediated by sulphuric and phosphoric acids. The as-prepared C-QDs showed blue, green and yellow luminescence without the addition of any surface-passivating agent. The C-QDs were further analyzed by UV-vis spectroscopy to measure the optical response of the organic compound. The energy gaps revealed narrow sizing of C-QDs in the semiconductor range. The optical refractive index and dielectric constant were investigated. The C-QDs size distribution was characterized. The results suggested an easy route to the large scale production of C-QDs materials.

Matched MeSH terms: Spectrum Analysis
Laser-induced breakdown spectroscopy-Raman: An effective complementary approach to analyze renal-calculi

Muhammed Shameem KM, Chawla A, Mallya M, Barik BK, Unnikrishnan VK, Kartha VB, et al.

J Biophotonics, 2018 06;11(6):e201700271.
PMID: 29411942 DOI: 10.1002/jbio.201700271

Presence of renal-calculi (kidney stones) in human urethra is being increasingly diagnosed over the last decade and is considered as one of the most painful urological disorders. Accurate analysis of such stones plays a vital role in the evaluation of urolithiasis patients and in turn helps the clinicians toward exact etiologies. Two highly complementary laser-based analytical techniques; laser-induced breakdown spectroscopy (LIBS) and micro-Raman spectroscopy have been used to identify the chemical composition of different types of renal-calculi. LIBS explores elemental characteristics while Raman spectroscopy provides molecular details of the sample. This complete information on the sample composition might help clinicians to identify the key aspects of the formation of kidney stones, hence assist in therapeutic management and to prevent recurrence. The complementarity of both techniques has been emphasized and discussed. LIBS spectra of different types of stones suggest the probable composition of it by virtue of the major, minor and trace elements detected from the sample. However, it failed to differentiate the crystalline form of different hydrates of calcium oxalate stone. This lacuna was overcome by the use of Raman spectroscopy and these results are compared with conventional chemical analysis.

Matched MeSH terms: Spectrum Analysis, Raman
Fulltext Peptidomics dataset: Blood plasma and serum samples of healthy donors fractionated on a set of chromatography sorbents

Arapidi G, Osetrova M, Ivanova O, Butenko I, Saveleva T, Pavlovich P, et al.

Data Brief, 2018 Jun;18:1204-1211.
PMID: 29900295 DOI: 10.1016/j.dib.2018.04.018

Blood as connective tissue potentially contains evidence of all processes occurring within the organism, at least in trace amounts (Petricoin et al., 2006) [1]. Because of their small size, peptides penetrate cell membranes and epithelial barriers more freely than proteins. Among the peptides found in blood, there are both fragments of proteins secreted by various tissues and performing their function in plasma and receptor ligands: hormones, cytokines and mediators of cellular response (Anderson et al., 2002) [2]. In addition, in minor amounts, there are peptide disease markers (for example, oncomarkers) and even foreign peptides related to pathogenic organisms and infection agents. To propose an approach for detailed peptidome characterization, we carried out an LC-MS/MS analysis of blood serum and plasma samples taken from 20 healthy donors on a TripleTOF 5600+ mass-spectrometer. We prepared samples based on our previously developed method of peptide desorption from the surface of abundant blood plasma proteins followed by standard chromatographic steps (Ziganshin et al., 2011) [3]. The mass-spectrometry peptidomics data presented in this article have been deposited to the ProteomeXchange Consortium (Deutsch et al., 2017) [4] via the PRIDE partner repository with the dataset identifier PXD008141 and 10.6019/PXD008141.

Matched MeSH terms: Spectrum Analysis
Fulltext A Review of Gelatin Source Authentication Methods

Hameed AM, Asiyanbi-H T, Idris M, Fadzillah N, Mirghani MES

Trop Life Sci Res, 2018 Jul;29(2):213-227.
PMID: 30112151 MyJurnal DOI: 10.21315/tlsr2018.29.2.15

Gelatin is a very popular pharmaceutical and food ingredient and the most studied ingredient in Halal researches. Interest in source gelatin authentication is based on religious and cultural beliefs, food fraud prevention and health issues. Seven gelatin authentication methods that have been developed include: nucleic acid based, immunochemical, electrophoretic analysis, spectroscopic, mass-spectrometric, chromatographic-chemometric and chemisorption methods. These methods are time consuming, and require capital intensive equipment with huge running cost. Reliability of gelatin authentication methods is challenged mostly by transformation of gelatin during processing and close similarities among gelatin structures. This review concisely presents findings and challenges in this research area and suggests needs for more researches on development of rapid authentication method and process-transformed gelatins.

Matched MeSH terms: Spectrum Analysis
Antibacterial evaluation of silver nanoparticles synthesized from lychee peel: individual versus antibiotic conjugated effects

Perveen S, Safdar N, Chaudhry GE, Yasmin A

World J Microbiol Biotechnol, 2018 Jul 14;34(8):118.
PMID: 30008019 DOI: 10.1007/s11274-018-2500-1

This paper describes the extracellular synthesis of silver nanoparticles from waste part of lychee fruit (peel) and their conjugation with selected antibiotics (amoxicillin, cefixim, and streptomycin). FTIR studies revealed the reduction of metallic silver and stabilization of silver nanoparticles and their conjugates due to the presence of CO (carboxyl), OH (hydroxyl) and CH (alkanes) groups. The size of conjugated nanoparticles varied ranging from 3 to 10 nm as shown by XRD. TEM image revealed the spherical shape of biosynthesized silver nanoparticles. Conjugates of amoxicillin and cefixim showed highest antibacterial activity (147.43 and 107.95%, respectively) against Gram-negative bacteria i.e. Alcaligenes faecalis in comparison with their control counterparts. The highest reduction in MIC was noted against Gram-positive strains i.e. Enterococcus faecium (75%) and Microbacterium oxydans (75%) for amoxicillin conjugates. Anova two factor followed by two-tailed t test showed non-significant results both in case of cell leakage and protein estimation between nanoparticles and conjugates of amoxicillin, cefixime and streptomycin. In case of MDA release, non-significant difference among the test samples against the selected strains. Our study found green-synthesized silver nanoparticles as effective antibacterial bullet against both Gram positive and Gram negative bacteria, but they showed a more promising effect on conjugation with selected antibiotics against Gram negative type.

Matched MeSH terms: Spectrum Analysis
In vitro assessment of ribose modified two-step etch-and-rinse dentine adhesive

Daood U, Tsoi JKH, Neelakantan P, Matinlinna JP, Omar HAK, Al-Nabulsi M, et al.

Dent Mater, 2018 08;34(8):1175-1187.
PMID: 29779627 DOI: 10.1016/j.dental.2018.05.005

OBJECTIVE: Collagen fibrils aid in anchoring resin composite restorations to the dentine substrate. The aim of the study was to investigate effect of non-enzymatic glycation on bond strength and durability of demineralized dentine specimens in a modified two-step etch-and-rinse dentine adhesive.
METHODS: Dentine surfaces were etched with 37% phosphoric acid, bonded with respective in vitro ethanol and acetone adhesives modified with (m/m, 0, 1%, 2% and 3% ribose), restored with restorative composite-resin, and sectioned into resin-dentine slabs and beams to be stored for 24h or 12 months in artificial saliva. Bond-strength testing was performed with bond failure analysis. Pentosidine assay was performed on demineralized ribose modified dentine specimens with HPLC sensitive fluorescent detection. The structural variations of ribose-modified dentine were analysed using TEM and human dental pulpal cells were used for cell viability. Three-point bending test of ribose-modified dentine beams were performed and depth of penetration of adhesives evaluated with micro-Raman spectroscopy. The MMP-2 and cathepsin K activities in ribose-treated dentine powder were also quantified using ELISA. Bond strength data was expressed using two-way ANOVA followed by Tukey's test. Paired T tests were used to analyse the specimens for pentosidine crosslinks. The modulus of elasticity and dentinal MMP-2 and cathepsin K concentrations was separately analyzed using one-way ANOVA.
RESULTS: The incorporation of RB in the experimental two-step etch-and-rinse adhesive at 1% improved the adhesive bond strength without adversely affecting the degree of polymerisation. The newly developed adhesive increases the resistance of dentine collagen to degradation by inhibiting endogenous matrix metalloproteinases and cysteine cathepsins. The application of RB to acid-etched dentine helps maintain the mechanical properties.
SIGNIFICANCE: The incorporation of 1%RB can be considered as a potential candidate stabilizing resin dentine bond.

Matched MeSH terms: Spectrum Analysis, Raman
Fulltext A Hydrogen Gas Sensor Based on TiO₂ Nanoparticles on Alumina Substrate

Mohd Chachuli SA, Hamidon MN, Mamat MS, Ertugrul M, Abdullah NH

Sensors (Basel), 2018 Aug 01;18(8).
PMID: 30071579 DOI: 10.3390/s18082483

High demand of semiconductor gas sensor works at low operating temperature to as low as 100 °C has led to the fabrication of gas sensor based on TiO₂ nanoparticles. A sensing film of gas sensor was prepared by mixing the sensing material, TiO₂ (P25) and glass powder, and B₂O₃ with organic binder. The sensing film was annealed at temperature of 500 °C in 30 min. The morphological and structural properties of the sensing film were characterized by field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The gas sensor was exposed to hydrogen with concentration of 100⁻1000 ppm and was tested at different operating temperatures which are 100 °C, 200 °C, and 300 °C to find the optimum operating temperature for producing the highest sensitivity. The gas sensor exhibited p-type conductivity based on decreased current when exposed to hydrogen. The gas sensor showed capability in sensing low concentration of hydrogen to as low as 100 ppm at 100 °C.

Matched MeSH terms: Spectrum Analysis
Biophysical characterization of a recombinant lipase KV1 from Acinetobacter haemolyticus in relation to pH and temperature

Batumalaie K, Khalili E, Mahat NA, Huyop F, Wahab RA

Biochimie, 2018 Sep;152:198-210.
PMID: 30036604 DOI: 10.1016/j.biochi.2018.07.011

Spectroscopic and calorimetric methods were employed to assess the stability and the folding aspect of a novel recombinant alkaline-stable lipase KV1 from Acinetobacter haemolyticus under varying pH and temperature. Data on far ultraviolet-circular dichroism of recombinant lipase KV1 under two alkaline conditions (pH 8.0 and 12.0) at 40 °C reveal strong negative ellipticities at 208, 217, 222 nm, implying its secondary structure belonging to a α + β class with 47.3 and 39.0% ellipticity, respectively. Results demonstrate that lipase KV1 adopts its most stable conformation at pH 8.0 and 40 °C. Conversely, the protein assumes a random coil structure at pH 4.0 and 80 °C, evident from a strong negative peak at ∼ 200 nm. This blue shift suggests a general decline in enzyme activity in conjunction with the partially or fully unfolded state that invariably exposed more hydrophobic surfaces of the lipase protein. The maximum emission at ∼335 nm for pH 8.0 and 40 °C indicates the adoption of a favorable protein conformation with a high number of buried tryptophan residues, reducing solvent exposure. Appearance of an intense Amide I absorption band at pH 8.0 corroborates an intact secondary structure. A lower enthalpy value for pH 4.0 over pH 8.0 and 12.0 in the differential scanning calorimetric data corroborates the stability of the lipase at alkaline conditions, while a low Km (0.68 ± 0.03 mM) for tributyrin verifies the high affinity of lipase KV1 for the substrate. The data, herein offer useful insights into future structure-based tunable catalytic activity of lipase KV1.

Matched MeSH terms: Spectrum Analysis/methods
Fulltext Introduction to Photonics: Principles and the Most Recent Applications of Microstructures

Amiri IS, Azzuhri SRB, Jalil MA, Hairi HM, Ali J, Bunruangses M, et al.

Micromachines (Basel), 2018 Sep 11;9(9).
PMID: 30424385 DOI: 10.3390/mi9090452

Light has found applications in data transmission, such as optical fibers and waveguides and in optoelectronics. It consists of a series of electromagnetic waves, with particle behavior. Photonics involves the proper use of light as a tool for the benefit of humans. It is derived from the root word "photon", which connotes the tiniest entity of light analogous to an electron in electricity. Photonics have a broad range of scientific and technological applications that are practically limitless and include medical diagnostics, organic synthesis, communications, as well as fusion energy. This will enhance the quality of life in many areas such as communications and information technology, advanced manufacturing, defense, health, medicine, and energy. The signal transmission methods used in wireless photonic systems are digital baseband and RoF (Radio-over-Fiber) optical communication. Microwave photonics is considered to be one of the emerging research fields. The mid infrared (mid-IR) spectroscopy offers a principal means for biological structure analysis as well as nonintrusive measurements. There is a lower loss in the propagations involving waveguides. Waveguides have simple structures and are cost-efficient in comparison with optical fibers. These are important components due to their compactness, low profile, and many advantages over conventional metallic waveguides. Among the waveguides, optofluidic waveguides have been found to provide a very powerful foundation for building optofluidic sensors. These can be used to fabricate the biosensors based on fluorescence. In an optical fiber, the evanescent field excitation is employed to sense the environmental refractive index changes. Optical fibers as waveguides can be used as sensors to measure strain, temperature, pressure, displacements, vibrations, and other quantities by modifying a fiber. For some application areas, however, fiber-optic sensors are increasingly recognized as a technology with very interesting possibilities. In this review, we present the most common and recent applications of the optical fiber-based sensors. These kinds of sensors can be fabricated by a modification of the waveguide structures to enhance the evanescent field; therefore, direct interactions of the measurand with electromagnetic waves can be performed. In this research, the most recent applications of photonics components are studied and discussed.

Matched MeSH terms: Spectrum Analysis
Fulltext Impact of TiO₂ Nanotubes' Morphology on the Photocatalytic Degradation of Simazine Pollutant

Meriam Suhaimy SH, Lai CW, Tajuddin HA, Samsudin EM, Johan MR

Materials (Basel), 2018 Oct 23;11(11).
PMID: 30360462 DOI: 10.3390/ma11112066

There are various approaches to enhancing the catalytic properties of TiO₂, including modifying its morphology by altering the surface reactivity and surface area of the catalyst. In this study, the primary aim is to enhance the photocatalytic activity by changing the TiO₂ nanotubes' architecture. The highly ordered infrastructure is favorable for a better charge carrier transfer. It is well known that anodization affects TiO₂ nanotubes' structure by increasing the anodization duration which in turn influence the photocatalytic activity. The characterizations were conducted by FE-SEM (fiend emission scanning electron microscopy), XRD (X-ray diffraction), RAMAN (Raman spectroscopy), EDX (Energy dispersive X-ray spectroscopy), UV-Vis (Ultraviolet visible spectroscopy) and LCMS/MS/MS (liquid chromatography mass spectroscopy). We found that the morphological structure is affected by the anodization duration according to FE-SEM. The photocatalytic degradation shows a photodegradation rate of k = 0.0104 min-1. It is also found that a mineralization of Simazine by our prepared TiO₂ nanotubes leads to the formation of cyanuric acid. We propose three Simazine photodegradation pathways with several intermediates identified.

Matched MeSH terms: Spectrum Analysis, Raman
Fulltext Synthesis and Optimization of Chitosan Nanoparticles Loaded with L-Ascorbic Acid and Thymoquinone

Othman N, Masarudin MJ, Kuen CY, Dasuan NA, Abdullah LC, Md Jamil SNA

Nanomaterials (Basel), 2018 Nov 07;8(11).
PMID: 30405074 DOI: 10.3390/nano8110920

The combination of compounds with different classes (hydrophobic and hydrophilic characters) in single chitosan carrier is a challenge due to the hydrophilicity of chitosan. Utilization of l-ascorbic acid (LAA) and thymoquinone (TQ) compounds as effective antioxidants is marred by poor bioavailability and uptake. Nanoparticles (NPs) solved the problem by functioning as a carrier for them because they have high surface areas for more efficient delivery and uptake by cells. This research, therefore, synthesized chitosan NPs (CNPs) containing LAA and TQ, CNP-LAA-TQ via ionic gelation routes as the preparation is non-toxic. They were characterized using electron microscopy, zetasizer, UV⁻VIS spectrophotometry, and infrared spectroscopy. The optimum CNP-LAA-TQ size produced was 141.5 ± 7.8 nm, with a polydispersity index (PDI) of 0.207 ± 0.013. The encapsulation efficiency of CNP-LAA-TQ was 22.8 ± 3.2% for LAA and 35.6 ± 3.6% for TQ. Combined hydrophilic LAA and hydrophobic TQ proved that a myriad of highly efficacious compounds with poor systemic uptake could be encapsulated together in NP systems to increase their pharmaceutical efficiency, indirectly contributing to the advancement of medical and pharmaceutical sectors.

Matched MeSH terms: Spectrum Analysis
Fulltext Sandwich Electrochemical Immunosensor for Early Detection of Tuberculosis Based on Graphene/Polyaniline-Modified Screen-Printed Gold Electrode

Mohd Azmi UZ, Yusof NA, Kusnin N, Abdullah J, Suraiya S, Ong PS, et al.

Sensors (Basel), 2018 Nov 14;18(11).
PMID: 30441776 DOI: 10.3390/s18113926

A rapid and sensitive sandwich electrochemical immunosensor was developed based on the fabrication of the graphene/polyaniline (GP/PANI) nanocomposite onto screen-printed gold electrode (SPGE) for detection of tuberculosis biomarker 10-kDa culture filtrate protein (CFP10). The prepared GP/PANI nanocomposite was characterized using Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). The chemical bonding and morphology of GP/PANI-modified SPGE were studied by Raman spectroscopy and FESEM coupled with energy dispersive X-ray spectroscopy, respectively. From both studies, it clearly showed that GP/PANI was successfully coated onto SPGE through drop cast technique. Cyclic voltammetry was used to study the electrochemical properties of the modified electrode. The effective surface area for GP/PANI-modified SPGE was enhanced about five times compared with bare SPGE. Differential pulse voltammetry was used to detect the CFP10 antigen. The GP/PANI-modified SPGE that was fortified with sandwich type immunosensor exhibited a wide linear range (20⁻100 ng/mL) with a low detection limit of 15 ng/mL. This proposed electrochemical immunosensor is sensitive, low sample volume, rapid and disposable, which is suitable for tuberculosis detection in real samples.

Matched MeSH terms: Spectrum Analysis, Raman
Geochemical distribution of the quarternary sendiment element of shallow estuary sea of sungai kelantan until the platform of south China sea, peninsular Malaysia

Che Aziz Ali, Kamal Roslan Mohamed, Nurul Afifah Mohd Radzir

Sains Malaysiana, 2018;47:1387-1392.

Analisis geokimia menggunakan kaedah ICP-MS menunjukkan taburan geokimia unsur di kawasan kajian dipengaruhi
oleh dua asalan sedimen berbeza iaitu daripada marin dan daratan. Unsur Ca dan Mg dikenal pasti sebagai unsur
marin, manakala unsur Al, Fe, Mn, Na, Cu, Cr, Zn dan Ni dikenal pasti sebagai unsur daratan. Unsur Ca dan Mg dikenal
pasti terhasil daripada proses penyahkapuran rangka dan hidupan marin seperti cengkerang moluska dan foraminifera.
Unsur benua berasal daripada granit dari Gunung Korbu dan Gunung Stong yang disaliri oleh Sungai Nenggiri dan
Sungai Galas, serta batuan argilit arenit yang berasal dari bahagian selatan dan tenggara Negeri Kelantan dari
Gunung Cintawangsa dan Gunung Stong dan disaliri oleh Sungai Lebir dan Sungai Galas. Unsur daripada batuan
induk membebaskan unsur kimia semasa luluhawa kimia dan telah dijerap oleh cas-cas negatif pada permukaan sedimen
halus seperti lempung dan lodak sebelum dimendapkan bersama di dalam kawasan kajian.

Matched MeSH terms: Spectrum Analysis
Fulltext Chemical profile of Xanthine Oxidase inhibitor fraction of Persicaria Hydropiper

Noor Hashim, N.H., Maulidiani, M., Mediani, A., Abas, F.

International Food Research Journal, 2018;25(3):1088-1094.
MyJurnal

Persicaria hydropiper, locally known as kesum, is an herb belongs to the family Polygonaceae. It has been used widely in many countries as food flavoring and possesses a wide range of medicinal values. The total phenolic content and xanthine oxidase inhibitory activity of the methanolic extract of P. hydropiper and fractions were determined spectrophotometrically. The butanol fraction was found to contain high phenolic content and was able to inhibit xanthine oxidase activity. Online profiling using liquid chromatography coupled with electrospray ionisation spectrometry (LC-ESIMS/MS) has revealed ten constituents in this active fraction. The major components were flavonoid derivatives and flavonoid sulphates, which were confirmed by comparison with an authentic standards as well as their MS/MS fragmentation patterns and UV spectra.

Matched MeSH terms: Spectrum Analysis
Fulltext Bimetallic PMMA@Alloy (Au-Ag) in 3D hot spots as highly sensitive substrate for high performance Surface-enhanced Raman Scattering (SERS)

Kassim, S., Tahrin, R.A.A., Rusdi, N.F., Harun, N.A.

ASM Science Journal, 2018;11(101):86-95.
MyJurnal

A feasible production of poly (methyl methacrylate)@alloy (gold-silver) core shell has
been presented as candidate in enhanced detection of surface enhanced Raman scattering
(SERS). Free emulsifier- emulsion synthesised PMMA sphere with average size of 419 nm in
diameter were used as core material for incorporation of alloy nanoparticles (6 nm) resulting
a core-shell structure. The fabrication of PMMA@alloy SERS substrate was successfully
done via self-assembly thus the produced SERS substrate that comprise of unique optical
properties combination arising from periodic core arrangement and plasmonic activity of
alloy nanoparticles. Alloy is bimetallic nanoparticles in which the combination of silver
(Ag) and gold (Au) present an absolutely improved light resistance as compared to single
metal alone with great surface plasmon resonance. Morphology and elemental analysis was
performed through scanning electron microscope (SEM) and the analysis showing species of
both Au and Ag in single alloy nanoparticles. The alloy nanoparticles were also observed to
homogenously coating the PMMA sphere. Surface plasmon resonance activity was maximum
at 476 nm obtained from UV-Visible spectroscopy. High surface production was observed
to have periodically arranged PMMA@alloy core -shell and potentially to be used as SERS
substrate.

Matched MeSH terms: Spectrum Analysis, Raman
Fulltext UV-visible chemometrics approach for the determination of selected adulterants in claimed premixed coffee

Muhammad Zul Fayyadh Azizo Rahman, Chong, Hui Wen, Lim, Vuanghao

Malaysian Journal of Medicine and Health Sciences, 2018;14(102):1-6.
MyJurnal

Adulterated premixed coffees have turned into an issue in Malaysia lately and have caught the eye of the authorities due to death reports linked to these products. The major cause of this issue is reported that these premixed coffees have passed food inspection test and eventually released to the market for public consumption. These coffees were claimed to be spiked with several sexual enhancers like sildenafil, tadalafil, and vardenafill, which are common drugs used to treat erectile dysfunction. Methods: Chemometrics approach using UV-Vis spectroscopy was developed to detect the selected sexual enhancer drugs found in commercial coffees by employing SIMCA-P software for the multivariate statistical analysis. Seven brands of coffee samples were purchased from local stores, and 30 sachets each were tested, hence totalling to 210 samples. Each sample was named H, J, G, W, N, T, and K, respectively. Results: Three multivariate models were generated, namely principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and partial least squares discriminant analysis (PLS-DA). OPLS-DA was selected as the best model for the overall results as it displayed minimal discriminate. Sildenafil, tadalafil, and vardenafil were detected in sample H, while vardenafil in brand J, and none in samples G, W, N, T, and K. Conclusion: OPLS-DA analysis showed discrimination for the sexual enhancer drugs in two brands of premixed coffee. The UV-Vis spectroscopy-based chemometrics method proved to be reliable and efficient in determining the selected drugs, as well as in saving time and cost.

Matched MeSH terms: Spectrum Analysis
Fulltext A facile hydrothermal approach for catalytic and optical behavior of tin oxide- graphene (SnO2/G) nanocomposite

Sagadevan S, Chowdhury ZZ, Johan MRB, Khan AA, Aziz FA, F Rafique R, et al.

PLoS One, 2018;13(10):e0202694.
PMID: 30273344 DOI: 10.1371/journal.pone.0202694

A cost-effective, facile hydrothermal approach was made for the synthesis of SnO2/graphene (Gr) nano-composites. XRD diffraction spectra clearly confirmed the presence of tetragonal crystal system of SnO2 which was maintaining its structure in both pure and composite materials' matrix. The stretching and bending vibrations of the functional groups were analyzed using FTIR analysis. FESEM images illustrated the surface morphology and the texture of the synthesized sample. HRTEM images confirmed the deposition of SnO2 nanoparticles over the surface of graphene nano-sheets. Raman Spectroscopic analysis was carried out to confirm the in-plane blending of SnO2 and graphene inside the composite matrix. The photocatalytic performance of the synthesized sample under UV irradiation using methylene blue dye was observed. Incorporation of grapheme into the SnO2 sample had increased the photocatalytic activity compared with the pure SnO2 sample. The electrochemical property of the synthesized sample was evaluated.

Matched MeSH terms: Spectrum Analysis, Raman
Fulltext Reinventing nano drug delivery systems for hydrophilic active ingredients in Ayurvedic lipid based formulations containing poly herbal decoction

Duraipandi S, Selvakumar V

J Ayurveda Integr Med, 2019 01 08;11(3):224-227.
PMID: 30635246 DOI: 10.1016/j.jaim.2018.01.008

BACKGROUND: Anu Tailam, an Ayurvedic medicated oil where 'anu' meant for atom and 'tailam' meant for oil and virtually meant for 'oil of subtle or atomic size particles'. Since the major active ingredients in this formulation are incorporated from the polyherbal decoction, it is expected to contain predominantly water soluble ingredients.
OBJECTIVES: It is hypothesized that these polar active botanical ingredients are present in the formulation should be either suspended in the form of submicron particles or entrapped in the submicron vesicular structures since the formulation did not show any precipitation or phase separation instead showed a monophasic oily liquid with very little moisture.
MATERIALS AND METHODS: In the present investigation, the micro architecture of the anu tailam is studied via column chromatography and high performance thin layer chromatography to prove the contents are polar hydrophilic compounds followed by optical microscopy, photon correlation Spectroscopy (PCS) and environmental scanning electron microscope (ESEM) to study the particle/vesicle size of the formulation.
RESULTS: In this study, it was proved that the formulation contained only polar ingredients and can be extracted in polar solvents like methanol and ethanol. It was also found that the formulation taken for study contained nano particles of the active botanical ingredients embedded in a network of vesicular structures of the lipid base.
CONCLUSION: The selected Ayurvedic formulation 'anutailam' found to contain novel nano drug delivery system to deliver water soluble ingredients across barriers.

Matched MeSH terms: Spectrum Analysis

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