Displaying publications 1 - 20 of 92 in total

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  1. Zamzuri NA, Abd-Aziz S, Rahim RA, Phang LY, Alitheen NB, Maeda T
    J Appl Microbiol, 2014 Apr;116(4):903-10.
    PMID: 24314059 DOI: 10.1111/jam.12410
    To isolate a bacterial strain capable of biotransforming ferulic acid, a major component of lignin, into vanillin and vanillic acid by a rapid colorimetric screening method.
    Matched MeSH terms: Colorimetry/methods*
  2. Yusof, F., Chowdhury, S., Faruck, M. O., Sulaiman, N.
    MyJurnal
    Cancer still presents enormous challenges in the medical world. Currently, the search for
    anticancer compounds has garnered a lot of interest, especially in finding them from the natural
    sources. In this study, by using Sulforhodamine B (SRB) colorimetric assay, compounds,
    extracted from supermeal worm (Zophobas morio) larvae using two types of acidified organic
    solvent (ethanol and isopropanol), were shown to inhibit the growth of a breast cancer line,
    MCF-7. A comparative study of the effect was carried out on a normal cell line, Vero. Results
    showed that, the two types of extracts inhibits growth of MCF-7 cell at varying degrees, on
    the other hand, have much less effect on Vero cell. Extracts analysed by UV-vis spectroscopy,
    showed peaks in the range of 260 to 280 nm, inferring the presence of aromatic amino acids,
    whereas the highest peak of 3.608 AU at 230 nm indicates the presence of peptide bonds. By
    Raman spectroscopy, peaks are observed at 1349 cm-1, 944 cm-1 and 841 cm-1 indicating the
    presence of Tyr, Try and Gly, confirming the UV-vis analyses. All results of analyses implied
    that the anticancer compounds contain peptides.
    Matched MeSH terms: Colorimetry
  3. Yee YC, Hashim R, Mohd Yahya AR, Bustami Y
    Sensors (Basel), 2019 May 31;19(11).
    PMID: 31159318 DOI: 10.3390/s19112511
    Glucose oxidase (EC 1.1.3.4) sensors that have been developed and widely used for glucose monitoring have generally relied on electrochemical principle. In this study, the potential use of colorimetric method for glucose detection utilizing glucose oxidase-magnetic cellulose nanocrystals (CNCs) is explored. Magnetic cellulose nanocrystals (magnetic CNCs) were fabricated using iron oxide nanoparticles (IONPs) and cellulose nanocrystals (CNCs) via electrostatic self-assembly technique. Glucose oxidase was successfully immobilized on magnetic CNCs using carbodiimide-coupling reaction. About 33% of GOx was successfully attached on magnetic CNCs, and the affinity of GOx-magnetic CNCs to glucose molecules was slightly higher than free enzymes. Furthermore, immobilization does not affect the specificity of GOx-magnetic CNCs towards glucose and can detect glucose from 0.25 mM to 2.5 mM. Apart from that, GOx-magnetic CNCs stored at 4 °C for 4 weeks retained 70% of its initial activity and can be recycled for at least ten consecutive cycles.
    Matched MeSH terms: Colorimetry/methods*
  4. Xue Mei L, Mohammadi Nafchi A, Ghasemipour F, Mat Easa A, Jafarzadeh S, Al-Hassan AA
    Int J Biol Macromol, 2020 Dec 01;164:4603-4612.
    PMID: 32941902 DOI: 10.1016/j.ijbiomac.2020.09.082
    The development of intelligent packaging based on natural and biodegradable resources is getting more attention by researchers in recent years. The aim of this study was to develop and characterize a pH-sensitive films based on sago starch and incorporated with anthocyanin from torch ginger. The pH-sensitive films were fabricated by casting method with incorporation of different torch ginger extract (TGE) concentration. The surface morphology, physicochemical, barrier, and mechanical properties as well as the pH-sensitivity of films were investigated. The film with the highest concentration of TGE showed the lowest tensile strength (4.26 N/m2), toughness (2.54 MJ/m3), Young's modulus (73.96 MPa) and water vapour permeability (2.6 × 10-4 g·m/day·kPa·m2). However, its elongation at break (85.14%), moisture content (0.27%) and water solubility (37.92%) were the highest compared to other films. pH sensitivity analysis showed that the films containing TGE extract, changes in colour by changing the pH. The colour of films changed from pink to slightly green as the pH increased from pH 4 to 9. Thus, the developed pH-sensitive film with torch ginger extract has potential as intelligent packaging for detection of food freshness or spoilage to ensure their quality and safe consumption.
    Matched MeSH terms: Colorimetry
  5. Xia N, Deng D, Wang Y, Fang C, Li SJ
    Int J Nanomedicine, 2018;13:2521-2530.
    PMID: 29731627 DOI: 10.2147/IJN.S154046
    Background: Prostate-specific antigen (PSA), a serine protease, is a biomarker for preoperative diagnosis and screening of prostate cancer and monitoring of its posttreatment.

    Methods: In this work, we reported a colorimetric method for clinical detection of PSA using gold nanoparticles (AuNPs) as the reporters. The method is based on ascorbic acid (AA)-induced in situ formation of AuNPs and Cu2+-catalyzed oxidation of AA. Specifically, HAuCl4 can be reduced into AuNPs by AA; Cu2+ ion can catalyze the oxidation of AA by O2 to inhibit the formation of AuNPs. In the presence of the PSA-specific peptide (DAHSSKLQLAPP)-modified gold-coated magnetic microbeads (MMBs; denoted as DAHSSKLQLAPP-MMBs), complexation of Cu2+ by the MMBs through the DAH-Cu2+ interaction depressed the catalyzed oxidation of AA and thus allowed for the formation of red AuNPs. However, once the peptide immobilized on the MMB surface was cleaved by PSA, the DAHSSKLQ segment would be released. The resultant LAPP fragment remaining on the MMB surface could not sequestrate Cu2+ to depress its catalytic activity toward AA oxidation. Consequently, no or less AuNPs were generated.

    Results: The linear range for PSA detection was found to be 0~0.8 ng/mL with a detection limit of 0.02 ng/mL. Because of the separation of cleavage step and measurement step, the interference of matrix components in biological samples was avoided.

    Conclusion: The high extinction coefficient of AuNPs facilitates the colorimetric analysis of PSA in serum samples. This work is helpful for designing of other protease biosensors by matching specific peptide substrates.

    Matched MeSH terms: Colorimetry/instrumentation; Colorimetry/methods*
  6. Wan Zuraida Wan Mohd Zain, Siti Nur Lisha Mohd Ghazali, Samsiah Jusoh
    ESTEEM Academic Journal, 2019;15(1):25-32.
    MyJurnal
    Oil palm or Elaeis guineens is a rich natural source of phenolic with flavonoid as the main constituents. These phenolics are potent antioxidants that can be used in the food industry, cosmetics and others. Therefore, the study was aimed to determine the effect of solvents which were methanol, ethyl acetate and hexane also different plant parts which were leaves, frond and fresh fruit bunch toward antioxidant activity (AOA), total phenolic content (TPC) and total flavonoid
    content (TFC). The antioxidant was analysed using the DPPH method, TPC by Ciocalteu assay and TFC by aluminium chloride colorimetric assay. The result from ANOVA indicated that there was a difference (P < 0.05) in the extracting ability of each solvent and different plant parts for AOA, TPC and TFC. Generally, the result suggested that methanol give the highest antioxidant
    activity, TPC and TFC compared to ethyl acetate and hexane. Therefore, the solvent used should be selected properly to allow for a high level of extraction efficiency.
    Matched MeSH terms: Colorimetry
  7. Thiha A, Ibrahim F
    Sensors (Basel), 2015;15(5):11431-41.
    PMID: 25993517 DOI: 10.3390/s150511431
    The enzyme-linked Immunosorbent Assay (ELISA) is the gold standard clinical diagnostic tool for the detection and quantification of protein biomarkers. However, conventional ELISA tests have drawbacks in their requirement of time, expensive equipment and expertise for operation. Hence, for the purpose of rapid, high throughput screening and point-of-care diagnosis, researchers are miniaturizing sandwich ELISA procedures on Lab-on-a-Chip and Lab-on-Compact Disc (LOCD) platforms. This paper presents a novel integrated device to detect and interpret the ELISA test results on a LOCD platform. The system applies absorption spectrophotometry to measure the absorbance (optical density) of the sample using a monochromatic light source and optical sensor. The device performs automated analysis of the results and presents absorbance values and diagnostic test results via a graphical display or via Bluetooth to a smartphone platform which also acts as controller of the device. The efficacy of the device was evaluated by performing dengue antibody IgG ELISA on 64 hospitalized patients suspected of dengue. The results demonstrate high accuracy of the device, with 95% sensitivity and 100% specificity in detection when compared with gold standard commercial ELISA microplate readers. This sensor platform represents a significant step towards establishing ELISA as a rapid, inexpensive and automatic testing method for the purpose of point-of-care-testing (POCT) in resource-limited settings.
    Matched MeSH terms: Colorimetry/instrumentation*
  8. Thavanathan J, Huang NM, Thong KL
    Biosens Bioelectron, 2014 May 15;55:91-8.
    PMID: 24368225 DOI: 10.1016/j.bios.2013.11.072
    The unique property of gold nanoparticles (Au NP) to induce colour change and the versatility of graphene oxides (GO) in surface modification makes them ideal in the application of colorimetric biosensor. Thus we developed a label free optical method to detect DNA hybridization through a visually observed colour change. The Au NP is conjugated to a DNA probe and is allowed to hybridize with the DNA target to the GO thus causing a change in colour from pinkish-red to purplish blue. Spectrophometry analysis gave a wavelength shift of 22 nm with 1 µM of DNA target. Sensitivity testing using serially diluted DNA conjugated GO showed that the optimum detection was at 63 nM of DNA target with the limit at 8 nM. This proves the possibility for the detection of DNA hybridization through the use of dual nanoparticle system by visual observation.
    Matched MeSH terms: Colorimetry/instrumentation*
  9. Thavanathan J, Huang NM, Thong KL
    Int J Nanomedicine, 2015;10:2711-22.
    PMID: 25897217 DOI: 10.2147/IJN.S74753
    We have developed a colorimetric biosensor using a dual platform of gold nanoparticles and graphene oxide sheets for the detection of Salmonella enterica. The presence of the invA gene in S. enterica causes a change in color of the biosensor from its original pinkish-red to a light purplish solution. This occurs through the aggregation of the primary gold nanoparticles-conjugated DNA probe onto the surface of the secondary graphene oxide-conjugated DNA probe through DNA hybridization with the targeted DNA sequence. Spectrophotometry analysis showed a shift in wavelength from 525 nm to 600 nm with 1 μM of DNA target. Specificity testing revealed that the biosensor was able to detect various serovars of the S. enterica while no color change was observed with the other bacterial species. Sensitivity testing revealed the limit of detection was at 1 nM of DNA target. This proves the effectiveness of the biosensor in the detection of S. enterica through DNA hybridization.
    Matched MeSH terms: Colorimetry/methods*
  10. Tan KH, Cham HY, Awala H, Ling TC, Mukti RR, Wong KL, et al.
    Nanoscale Res Lett, 2015 Dec;10(1):956.
    PMID: 26058517 DOI: 10.1186/s11671-015-0956-6
    Lubricant oils take significant part in current health and environmental considerations since they are an integral and indispensable component of modern technology. Antioxidants are probably the most important additives used in oils because oxidative deterioration plays a major role in oil degradation. Zeolite nanoparticles (NPs) have been proven as another option as green antioxidants in oil formulation. The anti-oxidative behavior of zeolite NPs is obvious; however, the phenomenon is still under investigation. Herein, a study of the effect of extra-framework cations stabilized on Linde Type L (LTL) zeolite NPs (ca. 20 nm) on inhibition of oxidation in palm oil-based lubricant oil is reported. Hydrophilic LTL zeolites with a Si/Al ratio of 3.2 containing four different inorganic cations (Li(+), Na(+), K(+), Ca(2+)) were applied. The oxidation of the lubricant oil was followed by visual observation, colorimetry, fourier transform infrared (FTIR) spectroscopy, (1)H NMR spectroscopy, total acid number (TAN), and rheology analyses. The effect of extra-framework cations to slow down the rate of oil oxidation and to control the viscosity of oil is demonstrated. The degradation rate of the lubricant oil samples is decreased considerably as the polarizability of cation is increased with the presence of zeolite NPs. More importantly, the microporous zeolite NPs have a great influence in halting the steps that lead to the polymerization of the oils and thus increasing the lifetime of oils.
    Matched MeSH terms: Colorimetry
  11. Tan BL, Norhaizan ME, Chan LC
    PMID: 29977314 DOI: 10.1155/2018/6578648
    Manilkara zapota (L.) P. Royen (family: Sapotaceae) is commonly called sapodilla, or locally known as ciku. The detailed mechanisms underlying Manilkara zapota leaf methanol extract against HeLa human cervical cancer cells have yet to be investigated. Therefore, our present study is designed to investigate the ability to induce apoptosis and the underlying mechanisms of Manilkara zapota leaf methanol extract inducing cytotoxicity in HeLa cells. The apoptotic cell death was assessed using Annexin V-propidium iodide staining. Intracellular reactive oxygen species (ROS) and mitochondrial membrane potential activities were measured using dichlorodihydrofluorescein diacetate and MitoLite Orange, respectively, by NovoCyte Flow Cytometer. Bax and Bcl-2 expression were evaluated using Enzyme-Linked Immunosorbent Assay. Caspase-3 activity was determined using a colorimetric assay. The associated biological interaction pathways were evaluated using quantitative real-time PCR. Our data showed that HeLa cells were relatively more sensitive to Manilkara zapota leaf methanol extract than other cancer cell lines studied. Overall analyses revealed that Manilkara zapota leaf methanol extract can inhibit the viability of HeLa cells, induce mitochondrial ROS generation, and inhibit nuclear factor-kappa B (NF-κB) and epidermal growth factor receptor (EGFR) transcriptional activities. Our results suggested that Manilkara zapota leaf methanol extract might represent a potential anticervical cancer agent.
    Matched MeSH terms: Colorimetry
  12. Syahir Habib, Mohd Yunus Abd Shukor, Nur Adeela Yasid, Wan Lutfi Wan Johari
    MyJurnal
    Petroleum hydrocarbons remain as the major contaminants that could be found across the world.
    Remediation approach through the utilisation of microbes as the bioremediation means widely
    recognised due to their outstanding values. As a result, scientific reports on the isolation and
    identification of new hydrocarbon-degrading strains were on the rise. Colourimetric-based assays
    are one of the fastest methods to identify the capability of hydrocarbon-degrading strains in both
    qualitative and quantitative assessment. In this study, the hydrocarbon-degrading potential of
    nine bacterial isolates was observed via 2,6-dichlorophenolindophenol (DCPIP) test. Two potent
    diesel-utilising isolates show a distinctive tendency to utilise aromatic (ADL15) and aliphatic
    (ADL36) hydrocarbons. Both isolates prove to be a good candidate for bioremediation of wide
    range of petroleum hydrocarbon components.
    Matched MeSH terms: Colorimetry
  13. Sundar UM, Ugusman A, Chua HK, Latip J, Aminuddin A
    Front Pharmacol, 2019;10:1033.
    PMID: 31607906 DOI: 10.3389/fphar.2019.01033
    Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelial nitric oxide synthase (eNOS). ADMA is degraded by dimethylarginine dimethylaminohydrolase (DDAH). Elevated levels of ADMA lead to reduction in nitric oxide (NO) production, which is linked to endothelial dysfunction and atherosclerosis. Piper sarmentosum is an herb that has shown stimulation on endothelial NO production by increasing both expression and activity of eNOS. Thus, this study determined whether the positive effect of P. sarmentosum on NO production is related to its modulation on the DDAH-ADMA pathway in cultured human umbilical vein endothelial cells (HUVEC) exposed to tumor necrosis factor-α (TNF-α). HUVEC were divided into four groups: control, treatment with 250 µg/ml of aqueous extract of P. sarmentosum leaves (AEPS), treatment with 30 ng/ml of TNF-α, and concomitant treatment with AEPS and TNF-α for 24 h. After treatments, HUVEC were collected to measure DDAH1 messenger RNA (mRNA) expression using quantitative real-time polymerase chain reaction. DDAH1 protein level was measured using enzyme-linked immunosorbent assay (ELISA), and DDAH enzyme activity was measured using colorimetric assay. ADMA concentration was measured using ELISA, and NO level was measured using Griess assay. Compared to control, TNF-α-treated HUVEC showed reduction in DDAH1 mRNA expression (P < 0.05), DDAH1 protein level (P < 0.01), and DDAH activity (P < 0.05). Treatment with AEPS successfully increased DDAH1 mRNA expression (P < 0.05), DDAH1 protein level (P < 0.01), and DDAH activity (P < 0.05) in TNF-α-treated HUVEC. Treatment with TNF-α caused an increase in ADMA level (P < 0.01) and a decrease in endothelial NO production (P < 0.001). Whereas treatment with AEPS was able to reduce ADMA level (P < 0.01) and restore NO (P < 0.001) in TNF-α-treated HUVEC. The results suggested that AEPS promotes endothelial NO production by stimulating DDAH activity and thus reducing ADMA level in TNF-α-treated HUVEC.
    Matched MeSH terms: Colorimetry
  14. Subramani IG, Perumal V, Gopinath SCB, Fhan KS, Mohamed NM
    Crit Rev Anal Chem, 2021 Mar 11.
    PMID: 33691533 DOI: 10.1080/10408347.2021.1889962
    Over the past decade, science has experienced a growing rise in nanotechnology with ground-breaking contributions. Through various laborious technologies, nanomaterials with different architectures from 0 D to 3 D have been synthesized. However, the 3 D flower-like organic-inorganic hybrid nanomaterial with the most direct one-pot green synthesis method has attracted widespread attention and instantly become research hotspot since its first allusion in 2012. Mild synthesis procedure, high surface-to-volume ratio, enhanced enzymatic activity and stability are the main factor for its rapid development. However, its lower mechanical strength, difficulties in recovery from the reaction system, lower loading capacity, poor reusability and accessibility of enzymes are fatal, which hinders its wide application in industry. This review first discusses the selection of non-enzymatic biomolecules for the synthesis of hybrid nanoflowers followed by the innovative advancements made in organic-inorganic hybrid nanoflowers to overcome aforementioned issues and to enhance their extensive downstream applications in transduction technologies. Besides, the role of hybrid nanoflower has been successfully utilized in many fields including, water remediation, biocatalyst, pollutant adsorption and decolourization, nanoreactor, biosensing, cellular uptake and others, accompanied with several quantification technologies, such as ELISA, electrochemical, surface plasmon resonance (SPR), colorimetric, and fluorescence were comprehensively reviewed.
    Matched MeSH terms: Colorimetry
  15. Sosroseno W, Sugiatno E
    Acta Biomed, 2008 Aug;79(2):110-6.
    PMID: 18788505
    BACKGROUND AND AIMS OF THE WORK: Nitric oxide (NO) has been reported to enhance the production of cAMP by hydroxyapatite (HA)-induced a human osteoblast cell line (HOS cells). The aim of the present study was to test the hypothesis that exogenous NO may up-regulate the proliferation of hydroxyapatite (HA)-induced HOS cells via the cyclic-AMP-protein kinase A (PKA) pathway.
    Matched MeSH terms: Colorimetry
  16. Siddiquee S, Saallah S, Bohari NA, Ringgit G, Roslan J, Naher L, et al.
    Nanomaterials (Basel), 2021 Apr 28;11(5).
    PMID: 33924923 DOI: 10.3390/nano11051142
    The present study reported a facile method for the determination of melamine in milk powder products based on the aggregation of reactant-free 5 nm gold nanoparticles (AuNPs). The strong electrostatic attraction between the positively charged exocyclic amine groups present in the melamine molecule and the negatively charged ions bound to the AuNPs induced aggregation of the AuNPs, resulting in visible color changes that could be seen with the naked eye and monitored by ultraviolet-visible (UV-Vis) absorbance spectra. The method shows high sensitivity with detection limits of 1 × 10-9 M for visual detection and 1 × 10-11 M for UV-Vis analysis, which is far below the safety limit of melamine ingestion in infant formula (1 ppm = 7.9 × 10-6 M) and the detection limit acquired by most AuNP-based melamine detection methods. Good recoveries were obtained over the range of 94.7-95.5% with a relative standard deviation of mean recovery (RSD) ranging from 1.40 to 5.81. The method provides a simple, feasible, fast and real-time detection of melamine adulterants in infant formula by the naked eye, without the aid of advanced instruments.
    Matched MeSH terms: Colorimetry
  17. Shafiu Kamba A, Zakaria ZA
    Biomed Res Int, 2014;2014:215097.
    PMID: 24734228 DOI: 10.1155/2014/215097
    Calcium carbonate (CaCO3) nanocrystals derived from cockle shells emerge to present a good concert in bone tissue engineering because of their potential to mimic the composition, structure, and properties of native bone. The aim of this study was to evaluate the biological response of CaCO3 nanocrystals on hFOB 1.19 and MC3T3 E-1 osteoblast cells in vitro. Cell viability and proliferation were assessed by MTT and BrdU assays, and LDH was measured to determine the effect of CaCO3 nanocrystals on cell membrane integrity. Cellular morphology was examined by SEM and fluorescence microscopy. The results showed that CaCO3 nanocrystals had no toxic effects to some extent. Cell proliferation, alkaline phosphatase activity, and protein synthesis were enhanced by the nanocrystals when compared to the control. Cellular interactions were improved, as indicated by SEM and fluorescent microscopy. The production of VEGF and TGF-1 was also affected by the CaCO3 nanocrystals. Therefore, bio-based CaCO3 nanocrystals were shown to stimulate osteoblast differentiation and improve the osteointegration process.
    Matched MeSH terms: Colorimetry
  18. Sayad A, Ibrahim F, Mukim Uddin S, Cho J, Madou M, Thong KL
    Biosens Bioelectron, 2018 Feb 15;100:96-104.
    PMID: 28869845 DOI: 10.1016/j.bios.2017.08.060
    Outbreaks of foodborne diseases have become a global health concern; hence, many improvements and developments have been made to reduce the risk of food contamination. We developed a centrifugal microfluidic automatic wireless endpoint detection system integrated with loop mediated isothermal amplification (LAMP) for monoplex pathogen detection. Six identical sets were designed on the microfluidic compact disc (CD) to perform 30 genetic analyses of three different species of foodborne pathogens. The consecutive loading, mixing, and aliquoting of the LAMP primers/reagents and DNA sample solutions were accomplished using an optimized square-wave microchannel, metering chambers and revulsion per minute (RPM) control. We tested 24 strains of pathogenic bacteria (Escherichia coli, Salmonella spp and Vibrio cholerae), with 8 strains of each bacterium, and performed DNA amplification on the microfluidic CD for 60min. Then, the amplicons of the LAMP reaction were detected using the calcein colorimetric method and further analysed via the developed electronic system interfaced with Bluetooth wireless technology to transmit the results to a smartphone. The system showed a limit of detection (LOD) of 3 × 10-5ngμL-1 DNA by analysing the colour change when tested with chicken meat spiked with the three pathogenic bacteria. Since the entire process was performed in a fully automated way and was easy to use, our microdevice is suitable for point-of-care (POC) testing with high simplicity, providing affordability and accessibility even to poor, resource-limited settings.
    Matched MeSH terms: Colorimetry/economics; Colorimetry/instrumentation*
  19. Salihu SO, Bakar NKA
    Environ Monit Assess, 2018 May 30;190(6):369.
    PMID: 29850927 DOI: 10.1007/s10661-018-6727-y
    The analysis of total organic carbon (TOC) by the American Public Health Association (APHA) closed-tube reflux colorimetric method requires potassium dichromate (K2Cr2O7), silver sulfate (AgSO4), and mercury (HgSO4) sulfate in addition to large volumes of both reagents and samples. The method relies on the release of oxygen from dichromate on heating which is consumed by carbon associated with organic compounds. The method risks environmental pollution by discharging large amounts of chromium (VI) and silver and mercury sulfates. The present method used potassium monochromate (K2CrO4) to generate the K2Cr2O7 on demand in the first phase. In addition, miniaturizing the procedure to semi microanalysis decreased the consumption of reagents and samples. In the second phase, mercury sulfate was eliminated as part of the digestion mixture through the introduction of sodium bismuthate (NaBiO3) for the removal of chlorides from the sample. The modified method, the potassium monochromate closed-tube colorimetry with sodium bismuthate chloride removal (KMCC-Bi), generates the potassium dichromate on demand and eliminates mercury sulfate. The semi microanalysis procedure leads to a 60% reduction in sample volume and ≈ 33.33 and 60% reduction in monochromate and silver sulfate consumption respectively. The LOD and LOQ were 10.17 and 33.90 mg L-1 for APHA, and 4.95 and 16.95 mg L-1 for KMCC-Bi. Recovery was between 83 to 98% APHA and 92 to 104% KMCC-Bi, while the RSD (%) ranged between 0.8 to 5.0% APHA and 0.00 to 0.62% KMCC-Bi. The method was applied for the UV-Vis spectrometry determination of COD in water and wastewater. Statistics was done by MINITAB 17 or MS Excel 2016. ᅟ Graphical abstract.
    Matched MeSH terms: Colorimetry/methods
  20. Ramanathan S, Gopinath SCB, Arshad MKM, Poopalan P, Anbu P
    Mikrochim Acta, 2019 07 18;186(8):546.
    PMID: 31321546 DOI: 10.1007/s00604-019-3696-y
    A genomic DNA-based colorimetric assay is described for the detection of the early growth factor receptor (EGFR) mutation, which is the protruding reason for non-small cell lung cancer. A DNA sequence was designed and immobilized on unmodified gold nanoparticles (GNPs). The formation of the respective duplex indicates the presence of an EGFR mutation. It is accompanied by the aggregation of the GNPs in the presence of monovalent ions, and it indicates the presence of an EGFR mutation. This is accompanied by a color change from red (520 nm) to purple (620 nm). Aggregation was evidenced by transmission electron microscopy, scanning electron microscopy and atomic force microscopy. The limit of detection is 313 nM of the mutant target strand. A similar peak shift was observed for 2.5 μM concentrations of wild type target. No significant peak shift was observed with probe and non-complementary DNA. Graphical abstract Schematic representation of high-specific genomic DNA sequence on gold nanoparticle (GNP) aggregation with sodium chloride (NaCl). It illustrates the detection method for EGFR mutation on lung cancer detection. Red and purple colors of tubes represent dispersed and aggregated GNP, respectively.
    Matched MeSH terms: Colorimetry
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