Displaying publications 41 - 60 of 166 in total

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  1. Fulltext An Ultrasensitive Voltammetric Genosensor for the Detection of Bacteria Vibrio cholerae in Vegetable and Environmental Water Samples
    Futra D, Tan LL, Lee SY, Lertanantawong B, Heng LY
    Biosensors (Basel), 2023 Jun 04;13(6).
    PMID: 37366981 DOI: 10.3390/bios13060616
    In view of the presence of pathogenic Vibrio cholerae (V. cholerae) bacteria in environmental waters, including drinking water, which may pose a potential health risk to humans, an ultrasensitive electrochemical DNA biosensor for rapid detection of V. cholerae DNA in the environmental sample was developed. Silica nanospheres were functionalized with 3-aminopropyltriethoxysilane (APTS) for effective immobilization of the capture probe, and gold nanoparticles were used for acceleration of electron transfer to the electrode surface. The aminated capture probe was immobilized onto the Si-Au nanocomposite-modified carbon screen printed electrode (Si-Au-SPE) via an imine covalent bond with glutaraldehyde (GA), which served as the bifunctional cross-linking agent. The targeted DNA sequence of V. cholerae was monitored via a sandwich DNA hybridization strategy with a pair of DNA probes, which included the capture probe and reporter probe that flanked the complementary DNA (cDNA), and evaluated by differential pulse voltammetry (DPV) in the presence of an anthraquninone redox label. Under optimum sandwich hybridization conditions, the voltammetric genosensor could detect the targeted V. cholerae gene from 1.0 × 10-17-1.0 × 10-7 M cDNA with a limit of detection (LOD) of 1.25 × 10-18 M (i.e., 1.1513 × 10-13 µg/µL) and long-term stability of the DNA biosensor up to 55 days. The electrochemical DNA biosensor was capable of giving a reproducible DPV signal with a relative standard deviation (RSD) of <5.0% (n = 5). Satisfactory recoveries of V. cholerae cDNA concentration from different bacterial strains, river water, and cabbage samples were obtained between 96.5% and 101.6% with the proposed DNA sandwich biosensing procedure. The V. cholerae DNA concentrations determined by the sandwich-type electrochemical genosensor in the environmental samples were correlated to the number of bacterial colonies obtained from standard microbiological procedures (bacterial colony count reference method).
    Matched MeSH terms: Electrochemical Techniques/methods
  2. Electroimmunodetection of cardiac C-reactive protein for determining myocardial Injury
    Gan X, Gong T, Zheng Y, Gopinath SCB, Zhao K
    Biotechnol Appl Biochem, 2021 Apr;68(2):272-278.
    PMID: 32275089 DOI: 10.1002/bab.1921
    C-reactive protein (CRP) is an acute phase reactant to be a marker of inflammation and has been correlated with the cardiac injury. An immunoassay was performed using anti-human CRP antibody on an InterDigitated electrode (IDE) sensor to determine and specify CRP concentration for diagnosing the condition of myocardial inflammation. To promote the detection, gold nanoparticle (GNP) was seeded on the aminated-IDE surface. Anti-CRP was hitched on the GNP-seeded surface and identified the abundance of CRP. The limit of quantification was found as 100 fM, and the higher current response was noticed by increasing CRP concentrations with the sensitivity at 1 pM. Furthermore, CRP-spiked human serum did not interfere the determination of CRP and increased the current response, indicating suitability for a real-life sample. Similarly, the control experiments with nonimmune antibody Troponin I are not showing the definite current responses, proving the selective identification of CRP. This method of diagnosing is needful to determine the cardiovascular injury at the right time.
    Matched MeSH terms: Electrochemical Techniques*
  3. Sonochemical and sustainable synthesis of graphene-gold (G-Au) nanocomposites for enzymeless and selective electrochemical detection of nitric oxide
    Geetha Bai R, Muthoosamy K, Zhou M, Ashokkumar M, Huang NM, Manickam S
    Biosens Bioelectron, 2017 Jan 15;87:622-629.
    PMID: 27616288 DOI: 10.1016/j.bios.2016.09.003
    In this study, a sonochemical approach was utilised for the development of graphene-gold (G-Au) nanocomposite. Through the sonochemical method, simultaneous exfoliation of graphite and the reduction of gold chloride occurs to produce highly crystalline G-Au nanocomposite. The in situ growth of gold nanoparticles (AuNPs) took place on the surface of exfoliated few-layer graphene sheets. The G-Au nanocomposite was characterised by UV-vis, XRD, FTIR, TEM, XPS and Raman spectroscopy techniques. This G-Au nanocomposite was used to modify glassy carbon electrode (GCE) to fabricate an electrochemical sensor for the selective detection of nitric oxide (NO), a critical cancer biomarker. G-Au modified GCE exhibited an enhanced electrocatalytic response towards the oxidation of NO as compared to other control electrodes. The electrochemical detection of NO was investigated by linear sweep voltammetry analysis, utilising the G-Au modified GCE in a linear range of 10-5000μM which exhibited a limit of detection of 0.04μM (S/N=3). Furthermore, this enzyme-free G-Au/GCE exhibited an excellent selectivity towards NO in the presence of interferences. The synergistic effect of graphene and AuNPs, which facilitated exceptional electron-transfer processes between the electrolyte and the GCE thereby improving the sensing performance of the fabricated G-Au modified electrode with stable and reproducible responses. This G-Au nanocomposite introduces a new electrode material in the sensitive and selective detection of NO, a prominent biomarker of cancer.
    Matched MeSH terms: Electrochemical Techniques/instrumentation; Electrochemical Techniques/methods*
  4. Sensitive voltammetric determination of paracetamol by poly (4-vinylpyridine)/multiwalled carbon nanotubes modified glassy carbon electrode
    Ghadimi H, Tehrani RM, Ali AS, Mohamed N, Ab Ghani S
    Anal Chim Acta, 2013 Feb 26;765:70-6.
    PMID: 23410628 DOI: 10.1016/j.aca.2012.12.039
    A novel glassy carbon electrode (GCE) modified with a composite film of poly (4-vinylpyridine) (P4VP) and multiwalled carbon nanotubes (P4VP/MWCNT GCE) was used for the voltammetric determination of paracetamol (PCT). This novel electrode displayed a combined effect of P4VP and MWCNT on the electro-oxidation of PCT in a solution of phosphate buffer at pH 7. Hence, conducting properties of P4VP along with the remarkable physical properties of MWCNTs might have combined effects in enhancing the kinetics of PCT oxidation. The P4VP/MWCNT GCE has also demonstrated excellent electrochemical activity toward PCT oxidation compared to that with bare GCE and MWCNT GCE. The anodic peak currents of PCT on the P4VP/MWCNT GCE were about 300 fold higher than that of the non-modified electrodes. By applying differential pulse voltammetry technique under optimized experimental conditions, a good linear ratio of oxidation peak currents and concentrations of PCT over the range of 0.02-450 μM with a limit of detection of 1.69 nM were achieved. This novel electrode was stable for more than 60 days and reproducible responses were obtained at 99% of the initial current of PCT without any influence of physiologically common interferences such as ascorbic acid and uric acid. The application of this electrode to determine PCT in tablets and urine samples was proposed.
    Matched MeSH terms: Electrochemical Techniques*
  5. Fulltext Optimisation of an electrochemical sensor based on bare gold electrode for detection of aluminium ion
    Gilbert Ringgit, Shafiquzzaman Siddiquee, Suryani Saallah, Mohammad Tamrin Mohamad Lal
    Borneo International Journal of Biotechnology, 2020;1(1):103-123.
    MyJurnal
    In this work, an electrochemical method for detection of trace amount of aluminium (Al3+), a heavy metal ion, based on a bare gold electrode (AuE) was developed. Current responses of the AuE under various type of electrolytes, redox indicators, pH, scan rate and accumulation time were investigated using cyclic voltammetry (CV) method to obtain the optimum conditions for Al3+ detection. The sensing properties of the AuE towards the target ion with different concentrations were investigated using differential pulse voltammetry (DPV) method. From the CV results, the optimal conditions for the detection of Al3+ were Tris-HCl buffer (0.1 M, pH 2) supported by 5 mM Prussian blue with scan rate and accumulation time respectively of 100 mVs−1 and 15 s. Under the optimum conditions, the DPV method was detected with different concentrations of aluminium ion ranging from 0.2 to 1.0 ppm resulted in a good linear regression r² = 0.9806. This result suggests that the optimisation of the basic parameters in electrochemical detection using AuE is crucial before further modification of the Au-electrode to improve the sensitivity and selectivity especially for the low concentration of ion detection. The developed method has a great potential for rapid detection of heavy metal ion (Al3+) in drinking water samples.
    Matched MeSH terms: Electrochemical Techniques
  6. DNA-RNA complementation on silicon wafer for thyroid cancer determination
    Gopinath SCB, Xuan S
    Biotechnol Appl Biochem, 2021 Jun;68(3):554-559.
    PMID: 32460382 DOI: 10.1002/bab.1961
    One of the current issues with thyroid tumor is early diagnosis as it makes the higher possibility of curing. This research was focused to detect and quantify the level of specific target sequence complementation of miR-222 with capture DNA sequence on interdigitated electrode (IDE) sensor. The aluminum electrode with the gap and finger sizes of 10 µm was fabricated on silicon wafer, further the surface was amine-functionalized for accommodating carboxylated-DNA probe. With DNA-target RNA complementation, the detection limit was attained to be 1 fM as estimated by a linear regression analysis [y = 1.5325x - 2.1171 R² = 0.9065] and the sensitivity was at the similar level. Current responses were higher by increasing the target RNA sequence concentrations. Control experiments with mismatched/noncomplementary sequences were failed to complement the capture DNA sequence immobilized on IDE, indicating the specific target validation. This research helps diagnosing and identifying the progression with thyroid tumor and miRNA being a potential "marker" in atypia diagnosis.
    Matched MeSH terms: Electrochemical Techniques*
  7. High-performance detection of an abdominal aortic aneurysm biomarker by immunosensing
    Guo S, Li Y, Li R, Zhang P, Wang Y, Gopinath SCB, et al.
    Biotechnol Appl Biochem, 2020 May;67(3):383-388.
    PMID: 31876964 DOI: 10.1002/bab.1877
    Abdominal aortic aneurysm (AAA) is a serious, life-threatening vascular disease that presents as an enlarged area of the aorta, which is the main artery that carries blood away from the heart. AAA may occur at any location in the aorta, but it is mainly found in the abdominal region. A ruptured AAA causes serious health issues, including death. Traditional imaging techniques, such as computed tomography angiogram, magnetic resonance imaging, and ultrasound sonography, have been used to identify AAAs. Circulating biomarkers have recently become attractive for diagnosing AAAs due to their cost-effectiveness compared to imaging. Insulin-like growth factor 1 (IGF-1), a secreted hormone vital for human atherosclerotic plaque stability, has been found to be an efficient biomarker for AAA identification. In this report, immunosensing was performed by using an InterDigitated electrode (IDE) sensor to detect circulating levels of IGF-1. The detection limit of IGF-1 was found to be 100 fM with this sensor. Moreover, related protein controls (IGF-2 and IGFBP3) were not detected with the same antibody, indicating selective IGF-1 detection. Thus, immunosensing by using an IDE sensor may help to effectively diagnose AAAs and represents a basic platform for further development.
    Matched MeSH terms: Electrochemical Techniques*
  8. Fabrication of an electrochemical sensor based on carbon nanotubes modified with gold nanoparticles for determination of valrubicin as a chemotherapy drug: valrubicin-DNA interaction
    Hajian R, Mehrayin Z, Mohagheghian M, Zafari M, Hosseini P, Shams N
    Mater Sci Eng C Mater Biol Appl, 2015 Apr;49:769-775.
    PMID: 25687007 DOI: 10.1016/j.msec.2015.01.072
    In this study, an electrochemical sensor was fabricated based on gold nanoparticles/ ethylenediamine/ multi-wall carbon-nanotubes modified gold electrode (AuNPs/en/MWCNTs/AuE) for determination of valrubicin in biological samples. Valrubicin was effectively accumulated on the surface of AuNPs/en/MWCNTs/AuE and produced a pair of redox peaks at around 0.662 and 0.578V (vs. Ag/AgCl) in citrate buffer (pH4.0). The electrochemical parameters including pH, buffer, ionic strength, scan rate and size of AuNPs have been optimized. There was a good linear correlation between cathodic peak current and concentration of valrubicin in the range of 0.5 to 80.0μmolL(-1) with the detection limit of 0.018μmolL(-1) in citrate buffer (pH4.0) and 0.1molL(-1) KCl. Finally, the constructed sensor was successfully applied for determination of valrubicin in human urine and blood serum. In further studies, the different sequences of single stranded DNA probes have been immobilized on the surface of AuNPs decorated on MWCNTs to study the interaction of oligonucleotides with valrubicin.
    Matched MeSH terms: Electrochemical Techniques/methods
  9. On-Demand Ligand-Base DNA Sensor with Electrochemical Impedance Spectroscopy
    Han H, Sabani NB, Nobusawa K, Takei F, Nakatani K, Yamashita I
    Anal Chem, 2023 Jul 04;95(26):9729-9733.
    PMID: 37341999 DOI: 10.1021/acs.analchem.3c01126
    We have developed a DNA sensor that can be finalized to detect a specific target on demand. The electrode surface was modified with 2,7-diamino-1,8-naphthyridine (DANP), a small molecule with nanomolar affinity for the cytosine bulge structure. The electrode was immersed in a solution of synthetic probe-DNA that had a cytosine bulge structure at one end and a complementary sequence to the target DNA at the other end. The strong binding between the cytosine bulge and DANP anchored the probe DNAs to the electrode surface, and the electrode became ready for target DNA sensing. The complementary sequence portion of the probe DNA can be changed as requested, allowing for the detection of a wide variety of targets. Electrochemical impedance spectroscopy (EIS) with the modified electrode detected target DNAs with a high sensitivity. The charge transfer resistance (Rct) extracted from EIS showed a logarithmic relationship with the concentration of target DNA. The limit of detection (LoD) was less than 0.01 μM. By this method, highly sensitive DNA sensors for various target sequences could be easily produced.
    Matched MeSH terms: Electrochemical Techniques/methods
  10. Characterisation of electrospun gelatine nanofibres encapsulated with Moringa oleifera bioactive extract
    Hani NM, Torkamani AE, Azarian MH, Mahmood KW, Ngalim SH
    J Sci Food Agric, 2017 Aug;97(10):3348-3358.
    PMID: 27981649 DOI: 10.1002/jsfa.8185
    BACKGROUND: Drumstick (Moringa oleifera) leaves have been used as a folk herbal medicine across many cultures since ancient times. This is most probably due to presence of phytochemicals possessing antioxidant properties, which could retard oxidative stress, and their degenerative effect. The current study deals with nanoencapsulation of Moringa oleifera (MO) leaf ethanolic extract within fish sourced gelatine matrix using electrospinning technique.

    RESULTS: The total phenolic and flavonoid content, radical scavenging (IC50 ) and metal reducing properties were 67.0 ± 2.5 mg GAE g-1 sample 32.0 ± 0.5 mg QE g-1 extract, 0.08 ± 0.01 mg mL-1 and 510 ± 10 µmol eq Fe(II) g-1 extract, respectively. Morphological and spectroscopic analysis of the fibre mats confirmed successful nanoencapsulation of MO extract within defect free nanofibres via electrospinning process. The percentage encapsulation efficiency (EE) was between 80% and 85%. Furthermore, thermal stability of encapsulated fibres, especially at 3% and 5% of core loading content, was significantly improved. Toxicological analysis revealed that the extract in its original and encapsulated form was safe for oral consumption.

    CONCLUSION: Overall, the present study showed the potential of ambient temperature electrospinning process as a safe nanoencapsulation method, where MO extract retained its antioxidative capacities. © 2016 Society of Chemical Industry.

    Matched MeSH terms: Electrochemical Techniques
  11. Carbon nanotube-based aptasensor for sensitive electrochemical detection of whole-cell Salmonella
    Hasan MR, Pulingam T, Appaturi JN, Zifruddin AN, Teh SJ, Lim TW, et al.
    Anal Biochem, 2018 08 01;554:34-43.
    PMID: 29870692 DOI: 10.1016/j.ab.2018.06.001
    In this study, an amino-modified aptasensor using multi-walled carbon nanotubes (MWCNTs)-deposited ITO electrode was prepared and evaluated for the detection of pathogenic Salmonella bacteria. An amino-modified aptamer (ssDNA) which binds selectively to whole-cell Salmonella was immobilised on the COOH-rich MWCNTs to produce the ssDNA/MWCNT/ITO electrode. The morphology of the MWCNT before and after interaction with the aptamers were observed using scanning electron microscopy (SEM). Cyclic voltammetry and electrochemical impedance spectroscopy techniques were used to investigate the electrochemical properties and conductivity of the aptasensor. The results showed that the impedance measured at the ssDNA/MWCNT/ITO electrode surface increased after exposure to Salmonella cells, which indicated successful binding of Salmonella on the aptamer-functionalised surface. The developed ssDNA/MWCNT/ITO aptasensor was stable and maintained linearity when the scan rate was increased from 10 mV s-1 to 90 mV s-1. The detection limit of the ssDNA/MWCNT/ITO aptasensor, determined from the sensitivity analysis, was found to be 5.5 × 101 cfu mL-1 and 6.7 × 101 cfu mL-1 for S. Enteritidis and S. Typhimurium, respectively. The specificity test demonstrated that Salmonella bound specifically to the ssDNA/MWCNT/ITO aptasensor surface, when compared with non-Salmonella spp. The prepared aptasensor was successfully applied for the detection of Salmonella in food samples.
    Matched MeSH terms: Electrochemical Techniques/methods*; Electrochemical Techniques/statistics & numerical data
  12. Fulltext Novel DNA Biosensor for Direct Determination of Carrageenan
    Hassan RA, Heng LY, Tan LL
    Sci Rep, 2019 04 23;9(1):6379.
    PMID: 31015498 DOI: 10.1038/s41598-019-42757-y
    A novel disposable electrochemical biosensor based on immobilized calf thymus double-stranded DNA (dsDNA) on the carbon-based screen-printed electrode (SPE) is developed for rapid biorecognition of carrageenan by using methylene blue (MB) redox indicator. The biosensor protocol for the detection of carrageenan is based on the concept of competitive binding of positively charged MB to the negatively charged dsDNA and carrageenan. The decrement in the MB cathodic peak current (ipc) signal as a result of the released MB from the immobilized dsDNA, and attracted to the carrageenan can be monitored via differential pulse voltammetry (DPV). The biosensor showed high sensitivity and selectivity to carrageenan at low concentration without interference from other polyanions such as alginate, gum arabic and starch. Calibration of the biosensor with carrageenan exhibited an excellent linear dependence from 1-10 mg L-1 (R2 = 0.98) with a detection limit of 0.08 mg L-1. The DNA-based carrageenan biosensor showed satisfactory reproducibility with 5.6-6.9% (n = 3) relative standard deviations (RSD), and possessing several advantages such as simplicity, fast and direct application to real sample analysis without any prior extensive sample treatments, particularly for seaweeds and food analyses.
    Matched MeSH terms: Electrochemical Techniques
  13. Au/Pd@rGO nanocomposite decorated with poly (L-Cysteine) as a probe for simultaneous sensitive electrochemical determination of anticancer drugs, Ifosfamide and Etoposide
    Hatamluyi B, Lorestani F, Es'haghi Z
    Biosens Bioelectron, 2018 Nov 30;120:22-29.
    PMID: 30144642 DOI: 10.1016/j.bios.2018.08.008
    The simultaneous measurement of the concentration of anticancer drugs with a fast, sensitive and accurate method in biological samples is a challenge for better monitoring of drug therapy and better determine the pharmacokinetics. An electrochemical sensor was developed for the simultaneous determination of anticancer drugs, Ifosfamide (IFO) and Etoposide (ETO) based on pencil graphite electrode modified with Au/Pd@rGO nanocomposite decorated with poly (L-Cysteine). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were utilized to study the properties of the modified electrode. The electrochemical behavior of IFO and ETO on the Au/Pd@rGO@p(L-Cys) modified electrode was investigated by cyclic voltammetry and differential pulse voltammetry (DPV) techniques and the obtained results confirmed its efficiency for the individual and simultaneous sensing of IFO and ETO. After optimization of electrochemical parameters, the fabricated sensor presented excellent performance in simultaneous determination of IFO and ETO with a wide linear range from 0.10 to 90.0 μM and 0.01 to 40.0 μM and low detection limits (3 Sb/m) of 9.210 nM and 0.718 nM, respectively. In addition, this study proved that the constructed sensor could be useful to simultaneous analysis of IFO and ETO in biological samples and pharmaceutical compounds.
    Matched MeSH terms: Electrochemical Techniques*
  14. A highly sensitive perovskite oxide sensor for detection of p-phenylenediamine in hair dyes
    He J, Sunarso J, Miao J, Sun H, Dai J, Zhang C, et al.
    J Hazard Mater, 2019 05 05;369:699-706.
    PMID: 30831522 DOI: 10.1016/j.jhazmat.2019.02.070
    Effective regulation of p-phenylenediamine (PPD), a widely used precursor of hair dye that is harmful to human health in large concentration, relies upon an accurate yet simple detection of PPD. In this context, amperometric electrode sensor based on perovskite oxide becomes attractive given its portability, low cost, high sensitivity, and rapid processing time. This work reports the systematic characterization of a series of Sr-doped PrCoO3-δ perovskite oxides with composition of Pr1-xSrxCoO3-δ(x = 0, 0.2, 0.4, 0.6, 0.8, and 1) for PPD detection in an alkaline solution. PSC82 deposited onto glassy carbon electrode (PSC82/GCE) generates the highest redox currents which correlates with the highest hydrogen peroxide intermediates (HO2-) yield and the σ*-orbital (eg) filling of Co that is closest to unity for PSC82. PSC82/GCE provides the highest sensitivities of 655 and 308 μA mM-1 cm-2 in PPD concentration range of 0.5-2,900 and 2,900-10,400 μM, respectively, with a limit of detection of 0.17 μM. PSC82/GCE additionally demonstrates high selectivity to PPD and long term stability during 50 consecutive cyclic voltammetry scans and over 1-month storage period. The potential applicability of PSC82/GCE was also demonstrated by confirming the presence of very low concentration of PPD of below 0.5% in real hair dyes.
    Matched MeSH terms: Electrochemical Techniques
  15. Fulltext Highly exposed {001} facets of titanium dioxide modified with reduced graphene oxide for dopamine sensing
    How GT, Pandikumar A, Ming HN, Ngee LH
    Sci Rep, 2014;4:5044.
    PMID: 24853929 DOI: 10.1038/srep05044
    Titanium dioxide (TiO2) with highly exposed {001} facets was synthesized through a facile solvo-thermal method and its surface was decorated by using reduced graphene oxide (rGO) sheets. The morphology and chemical composition of the prepared rGO/TiO2 {001} nanocomposite were examined by using suitable characterization techniques. The rGO/TiO2 {001} nanocomposite was used to modify glassy carbon electrode (GCE), which showed higher electrocatalytic activity towards the oxidation of dopamine (DA) and ascorbic acid (AA), when compared to unmodified GCE. The differential pulse voltammetric studies revealed good sensitivity and selectivity nature of the rGO/TiO2 {001} nanocomposite modified GCE for the detection of DA in the presence of AA. The modified GCE exhibited a low electrochemical detection limit of 6 μM over the linear range of 2-60 μM. Overall, this work provides a simple platform for the development of GCE modified with rGO/TiO2 {001} nanocomposite with highly exposed {001} facets for potential electrochemical sensing applications.
    Matched MeSH terms: Electrochemical Techniques
  16. Combination of Cyclodextrin and Ionic Liquid in Analytical Chemistry: Current and Future Perspectives
    Hui BY, Raoov M, Zain NNM, Mohamad S, Osman H
    Crit Rev Anal Chem, 2017 Sep 03;47(5):454-467.
    PMID: 28453309 DOI: 10.1080/10408347.2017.1320936
    The growth in driving force and popularity of cyclodextrin (CDs) and ionic liquids (ILs) as promising materials in the field of analytical chemistry has resulted in an exponentially increase of their exploitation and production in analytical chemistry field. CDs belong to the family of cyclic oligosaccharides composing of α-(1,4) linked glucopyranose subunits and possess a cage-like supramolecular structure. This structure enables chemical reactions to proceed between interacting ions, radical or molecules in the absence of covalent bonds. Conversely, ILs are an ionic fluids comprising of only cation and anion often with immeasurable vapor pressure making them as green or designer solvent. The cooperative effect between CD and IL due to their fascinating properties, have nowadays contributed their footprints for a better development in analytical chemistry nowadays. This comprehensive review serves to give an overview on some of the recent studies and provides an analytical trend for the application of CDs with the combination of ILs that possess beneficial and remarkable effects in analytical chemistry including their use in various sample preparation techniques such as solid phase extraction, magnetic solid phase extraction, cloud point extraction, microextraction, and separation techniques which includes gas chromatography, high-performance liquid chromatography, capillary electrophoresis as well as applications of electrochemical sensors as electrode modifiers with references to recent applications. This review will highlight the nature of interactions and synergic effects between CDs, ILs, and analytes. It is hoped that this review will stimulate further research in analytical chemistry.
    Matched MeSH terms: Electrochemical Techniques/methods
  17. Cardiovascular biomarker troponin I biosensor: Aptamer-gold-antibody hybrid on a metal oxide surface
    Hui H, Gopinath SCB, Ismail ZH, Chen Y, Pandian K, Velusamy P
    Biotechnol Appl Biochem, 2023 Apr;70(2):581-591.
    PMID: 35765758 DOI: 10.1002/bab.2380
    Myocardial infarction (MI) is highly related to cardiac arrest leading to death and organ damage. Radiological techniques and electrocardiography have been used as preliminary tests to diagnose MI; however, these techniques are not sensitive enough for early-stage detection. A blood biomarker-based diagnosis is an immediate solution, and due to the high correlation of troponin with MI, it has been considered to be a gold-standard biomarker. In the present research, the cardiac biomarker troponin I (cTnI) was detected on an interdigitated electrode sensor with various surface interfaces. To detect cTnI, a capture aptamer-conjugated gold nanoparticle probe and detection antibody probe were utilized and compared through an alternating sandwich pattern. The surface metal oxide morphology of the developed sensor was proven by microscopic assessments. The limit of detection with the aptamer-gold-cTnI-antibody sandwich pattern was 100 aM, while it was 1 fM with antibody-gold-cTnI-aptamer, representing 10-fold differences. Further, the high performance of the sensor was confirmed by selective cTnI determination in serum, exhibiting superior nonfouling. These methods of determination provide options for generating novel assays for diagnosing MI.
    Matched MeSH terms: Electrochemical Techniques/methods
  18. Fulltext Electrochemical data of single and hybrid sol-gel coating precursors for aluminum alloy corrosion protection in 3.5% NaCl
    Hussin MH
    Data Brief, 2019 Feb;22:971-976.
    PMID: 30740480 DOI: 10.1016/j.dib.2019.01.029
    The anti-corrosion performances of single(TEOS) and hybrid (APTES-TEOS) sol-gel coatings on Al alloy samples exposed to 3.5 wt% NaCl were evaluated employing electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The data acquired using the three corrosion analysis techniques were in accordance with each other where hybrid sol-gel coating offered the lowest corrosion rate and current density in comparison to the single precursor silanol coating. Tafel curves suggested that the hybrid silane coatings mitigate both the anodic and cathodic reactions simultaneously (mixed type inhibitor). These techniques justified that incorporation of hybrid sol-gel improved the Al corrosion protection performance considerably.
    Matched MeSH terms: Electrochemical Techniques
  19. Fulltext Cadmium Sulphide-Reduced Graphene Oxide-Modified Photoelectrode-Based Photoelectrochemical Sensing Platform for Copper(II) Ions
    Ibrahim I, Lim HN, Huang NM, Pandikumar A
    PLoS One, 2016;11(5):e0154557.
    PMID: 27176635 DOI: 10.1371/journal.pone.0154557
    A photoelectrochemical (PEC) sensor with excellent sensitivity and detection toward copper (II) ions (Cu2+) was developed using a cadmium sulphide-reduced graphene oxide (CdS-rGO) nanocomposite on an indium tin oxide (ITO) surface, with triethanolamine (TEA) used as the sacrificial electron donor. The CdS nanoparticles were initially synthesized via the aerosol-assisted chemical vapor deposition (AACVD) method using cadmium acetate and thiourea as the precursors to Cd2+ and S2-, respectively. Graphene oxide (GO) was then dip-coated onto the CdS electrode and sintered under an argon gas flow (50 mL/min) for the reduction process. The nanostructured CdS was adhered securely to the ITO by a continuous network of rGO that also acted as an avenue to intensify the transfer of electrons from the conduction band of CdS. The photoelectrochemical results indicated that the ITO/CdS-rGO photoelectrode could facilitate broad UV-visible light absorption, which would lead to a higher and steady-state photocurrent response in the presence of TEA in 0.1 M KCl. The photocurrent decreased with an increase in the concentration of Cu2+ ions. The photoelectrode response for Cu2+ ion detection had a linear range of 0.5-120 μM, with a limit of detection (LoD) of 16 nM. The proposed PEC sensor displayed ultra-sensitivity and good selectivity toward Cu2+ ion detection.
    Matched MeSH terms: Electrochemical Techniques/methods*
  20. Selective and sensitive visible-light-prompt photoelectrochemical sensor of Cu2+ based on CdS nanorods modified with Au and graphene quantum dots
    Ibrahim I, Lim HN, Huang NM, Jiang ZT, Altarawneh M
    J Hazard Mater, 2020 06 05;391:122248.
    PMID: 32062348 DOI: 10.1016/j.jhazmat.2020.122248
    Nowadays, increasing the risk for copper leaching into the drinking water in homes, hotels and schools has become unresolved issues all around the countries such as Canada, the United States, and Malaysia. The leaching of copper in tap water is due to a combination of acidic water, damaged pipes, and corroded plumbing fixtures. To remedy this global problem, a triple interconnected structure of CdS/Au/GQDs was designed as a photo-to-electron conversion medium for a real time and selective visible-light-prompt photoelectrochemical (PEC) sensor for Cu2+ ions in real water samples. The synergistic interaction of the CdS/Au/GQDs enabled the smooth transportation of charge carriers to the charge collector and provided a channel to inhibit the charge recombination reaction. Thus, a detection limit of 2.27 nM was obtained, which is 10,000 fold lower than that of WHO's Guidelines for Drinking-water Quality (∼30 μM). The photocurrent reduction was negligible after 30 days of storage under ambient conditions, suggesting the high stability of photoelectrode. Moreover, the real-time monitoring of Cu2+ ions in real samples was performed with satisfactory results, confirming the capability of the investigated photoelectrode as the most practical detector for trace amounts of Cu2+ ions.
    Matched MeSH terms: Electrochemical Techniques*
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