Displaying publications 81 - 100 of 130 in total

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  1. Fulltext Classification of Human Daily Activities Using Ensemble Methods Based on Smartphone Inertial Sensors
    Ku Abd Rahim KN, Elamvazuthi I, Izhar LI, Capi G
    Sensors (Basel), 2018 Nov 26;18(12).
    PMID: 30486242 DOI: 10.3390/s18124132
    Increasing interest in analyzing human gait using various wearable sensors, which is known as Human Activity Recognition (HAR), can be found in recent research. Sensors such as accelerometers and gyroscopes are widely used in HAR. Recently, high interest has been shown in the use of wearable sensors in numerous applications such as rehabilitation, computer games, animation, filmmaking, and biomechanics. In this paper, classification of human daily activities using Ensemble Methods based on data acquired from smartphone inertial sensors involving about 30 subjects with six different activities is discussed. The six daily activities are walking, walking upstairs, walking downstairs, sitting, standing and lying. It involved three stages of activity recognition; namely, data signal processing (filtering and segmentation), feature extraction and classification. Five types of ensemble classifiers utilized are Bagging, Adaboost, Rotation forest, Ensembles of nested dichotomies (END) and Random subspace. These ensemble classifiers employed Support vector machine (SVM) and Random forest (RF) as the base learners of the ensemble classifiers. The data classification is evaluated with the holdout and 10-fold cross-validation evaluation methods. The performance of each human daily activity was measured in terms of precision, recall, F-measure, and receiver operating characteristic (ROC) curve. In addition, the performance is also measured based on the comparison of overall accuracy rate of classification between different ensemble classifiers and base learners. It was observed that overall, SVM produced better accuracy rate with 99.22% compared to RF with 97.91% based on a random subspace ensemble classifier.
    Matched MeSH terms: Biosensing Techniques/methods*
  2. Silver nanoparticles decorated polyaniline nanocomposite based electrochemical sensor for the determination of anticancer drug 5-fluorouracil
    Zahed FM, Hatamluyi B, Lorestani F, Es'haghi Z
    J Pharm Biomed Anal, 2018 Nov 30;161:12-19.
    PMID: 30142492 DOI: 10.1016/j.jpba.2018.08.004
    A highly efficient electrochemical sensor for the analysis of anticancer drug 5-fluorouracil (5-FU), is fabricated based on silver nanoparticles-polyaniline nanotube (AgNPs@PANINTs). AgNPs@PANINTs nanocomposite has been synthesized by a simple one-step method. Synthesized AgNPs@PANINTs nanocomposite was studied by Fourier transform infrared spectrometry, Scanning Electron Microscopy and Energy Dispersive X-ray. The fabricated PANINTs@AgNPs PGE was applied to the electrochemical sensing of 5-FU. Cyclic voltammetry and differential pulse voltammetry experiments illustrated high electro activity for the AgNPs@PANINTs nanocomposite. The study was explored using the Taguchi experimental design method. Electrochemical measurements using differential pulse voltammetry showed a wide linear relationship between 5-FU concentration and peak height within the range 1.0-300.0 μM with a low detection limit (0.06 μM). Also, the fabricated sensor showed excellent selectivity in the presence of two anticancer drugs and a number of other interfering compounds. The as-prepared sensor showed to be a promising device for a simple, rapid, and direct analysis of 5-FU.
    Matched MeSH terms: Biosensing Techniques/methods*
  3. 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: Biosensing Techniques/methods*
  4. Fulltext Development of Highly Sensitive Immunosensor for Clenbuterol Detection by Using Poly(3,4-ethylenedioxythiophene)/Graphene Oxide Modified Screen-Printed Carbon Electrode
    Talib NAA, Salam F, Sulaiman Y
    Sensors (Basel), 2018 Dec 07;18(12).
    PMID: 30544568 DOI: 10.3390/s18124324
    Clenbuterol (CLB) is an antibiotic and illegal growth promoter drug that has a long half-life and easily remains as residue and contaminates the animal-based food product that leads to various health problems. In this work, electrochemical immunosensor based on poly(3,4-ethylenedioxythiophene)/graphene oxide (PEDOT/GO) modified screen-printed carbon electrode (SPCE) for CLB detection was developed for antibiotic monitoring in a food product. The modification of SPCE with PEDOT/GO as a sensor platform was performed through electropolymerization, while the electrochemical assay was accomplished while using direct competitive format in which the free CLB and clenbuterol-horseradish peroxidase (CLB-HRP) in the solution will compete to form binding with the polyclonal anti-clenbuterol antibody (Ab) immobilized onto the modified electrode surface. A linear standard CLB calibration curve with R² = 0.9619 and low limit of detection (0.196 ng mL-1) was reported. Analysis of milk samples indicated that this immunosensor was able to detect CLB in real samples and the results that were obtained were comparable with enzyme-linked immunosorbent assays (ELISA).
    Matched MeSH terms: Biosensing Techniques/methods*
  5. Recent uses of carbon nanotubes & gold nanoparticles in electrochemistry with application in biosensing: A review
    Alim S, Vejayan J, Yusoff MM, Kafi AKM
    Biosens Bioelectron, 2018 Dec 15;121:125-136.
    PMID: 30205246 DOI: 10.1016/j.bios.2018.08.051
    The innovation of nanoparticles assumes a critical part of encouraging and giving open doors and conceivable outcomes to the headway of new era devices utilized as a part of biosensing. The focused on the quick and legitimate detecting of specific biomolecules using functionalized gold nanoparticles (Au NPs), and carbon nanotubes (CNTs) has turned into a noteworthy research enthusiasm for the most recent decade. Sensors created with gold nanoparticles or carbon nanotubes or in some cases by utilizing both are relied upon to change the very establishments of detecting and distinguishing various analytes. In this review, we will examine the current utilization of functionalized AuNPs and CNTs with other synthetic mixes for the creation of biosensor prompting to the location of particular analytes with low discovery cutoff and quick reaction.
    Matched MeSH terms: Biosensing Techniques/methods*
  6. Fulltext Gold nanoparticle-based colorimetric method for the detection of prostate-specific antigen
    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: Biosensing Techniques/methods
  7. DNA Switch: Toehold-Mediated DNA Isothermal Amplification for Dengue Serotyping
    Chan SK, Kuzuya A, Choong YS, Lim TS
    SLAS Discov, 2019 01;24(1):68-76.
    PMID: 30063871 DOI: 10.1177/2472555218791743
    The inherent ability of nucleic acids to recognize a complementary pair has gained wide popularity in DNA sensor applications. DNA molecules can be produced in bulk and easily incorporated with various nanomaterials for sensing applications. More complex designs and sophisticated DNA sensors have been reported over the years to allow DNA detection in a faster, cheaper, and more convenient manner. Here, we report a DNA sensor designed to function like a switch to turn "on" silver nanocluster (AgNC) generation in the presence of a specific DNA target. By defining the probe region sequence, we are able to tune the color of the AgNC generated in direct relation to the different targets. As a proof of concept, we used dengue RNA-dependent RNA polymerase conserved sequences from all four serotypes as targets. This method was able to distinguish each dengue serotype by generating the serotype-respective AgNCs. The DNA switch was also able to identify and amplify the correct target in a mixture of targets with good specificity. This strategy has a detection limit of between 1.5 and 2.0 µM depending on the sequence of AgNC. The DNA switch approach provides an attractive alternative for single-target or multiplex DNA detection.
    Matched MeSH terms: Biosensing Techniques/methods
  8. Amplification-free and direct fluorometric determination of telomerase activity in cell lysates using chimeric DNA-templated silver nanoclusters
    Lee ST, Rahman R, Muthoosamy K, Mohamed NAH, Su X, Tayyab S, et al.
    Mikrochim Acta, 2019 01 09;186(2):81.
    PMID: 30627857 DOI: 10.1007/s00604-018-3194-7
    A fluorogenic probe has been developed for determination of telomerase activity using chimeric DNA-templated silver nanoclusters (AgNCs). The formation of AgNCs was investigated before (route A) and after (route B) telomerase elongation reaction. Both routes caused selective quenching of the yellow emission of the AgNCs (best measured at excitation/emission wavelength of 470/557 nm) in telomerase-positive samples. The quenching mechanism was studied using synthetically elongated DNA to mimic the telomerase-catalyzed elongation. The findings show that quenching is due to the formation of parallel G-quadruplexes with a -TTA- loop in the telomerase elongated products. The assay was validated using different cancer cell extracts, with intra- and interassay coefficients of variations of <9.8%. The limits of detection for MCF7, RPMI 2650 and HT29 cell lines are 15, 22 and 39 cells/μL. This represents a distinct improvement over the existing telomeric repeat amplification protocol (TRAP) assay in terms of time, sensitivity and cost. Graphical Abstract A method was developed using chimeric DNA-templated silver nanoclusters to detect telomerase activity directly in cell extracts. The sensitivity of this new method outperforms the traditional TRAP assay, and without the need for amplification.
    Matched MeSH terms: Biosensing Techniques/methods
  9. Current state of green reduction strategies: Solution-processed reduced graphene oxide for healthcare biodetection
    Taniselass S, Md Arshad MK, Gopinath SCB
    Mater Sci Eng C Mater Biol Appl, 2019 Mar;96:904-914.
    PMID: 30606604 DOI: 10.1016/j.msec.2018.11.062
    Reduction of graphene oxide becomes an alternative way to produce a scalable graphene and the resulting nanomaterial namely reduced graphene oxide (rGO) has been utilized in a wide range of potential applications. In this article, the level of green reduction strategies, especially the solution-based reduction methods are overviewed based on recent progression, to get insights towards biomedical applications. The degrees of gaining tips with the solution-based green reduction methods, conditions, complexity and the resulting rGO characteristics have been elucidated comparatively. Moreover, the application of greenly produced rGO in electrochemical biosensors has been elucidated as well as their electrical performance in term of linear range and limit of detections for various healthcare biological analytes. In addition, the characterization scheme for graphene-based materials and the analyses on the reduction especially for the solution-based green reduction methods are outlined for the future endeavours.
    Matched MeSH terms: Biosensing Techniques/methods*
  10. High-performance interactive analysis of split aptamer and HIV-1 Tat on multiwall carbon nanotube-modified field-effect transistor
    Fatin MF, Rahim Ruslinda A, Gopinath SCB, Arshad MKM
    Int J Biol Macromol, 2019 Mar 15;125:414-422.
    PMID: 30529550 DOI: 10.1016/j.ijbiomac.2018.12.066
    Interaction between split RNA aptamer and the clinically important target, HIV-1 Tat was investigated on a biosensing surface transduced by functionally choreographed multiwall carbon nanotubes (MWCNTs). Acid oxidation was performed to functionalize MWCNTs with carboxyl functional groups. X-ray photoelectron spectroscopy analysis had profound ~2.91% increment in overall oxygen group and ~1% increment was noticed with a specific carboxyl content owing to CO and OCO bonding. The interaction between split RNA aptamer and HIV-1 Tat protein was quantified by electrical measurements with the current signal (Ids) over a gate voltage (Vgs). Initially, 34.4 mV gate voltage shift was observed by the immobilization of aptamer on MWCNT. With aptamer and HIV-1 Tat interaction, the current flow was decreased with the concomitant gate voltage shift of 23.5 mV. The attainment of sensitivity with split aptamer and HIV-1 Tat interaction on the fabricated device was 600 pM. To ensure the genuine interaction of aptamer with HIV-1 Tat, other HIV-1 proteins, Nef and p24 were interacted with aptamer and they displayed the negligible interferences with gate voltage shift of 3.5 mV and 5.7 mV, which shows 4 and 2.5 folds lesser than HIV-1 Tat interaction, respectively.
    Matched MeSH terms: Biosensing Techniques/methods
  11. Probe-specific loop-mediated isothermal amplification magnetogenosensor assay for rapid and specific detection of pathogenic Leptospira
    Nurul Najian AB, Foo PC, Ismail N, Kim-Fatt L, Yean CY
    Mol Cell Probes, 2019 04;44:63-68.
    PMID: 30876924 DOI: 10.1016/j.mcp.2019.03.001
    This study highlighted the performance of the developed integrated loop-mediated isothermal amplification (LAMP) coupled with a colorimetric DNA-based magnetogenosensor. The biosensor operates through a DNA hybridization system in which a specific designed probe captures the target LAMP amplicons. We demonstrated the magnetogenosensor assay by detecting pathogenic Leptospira, which causes leptospirosis. The color change of the assay from brown to blue indicated a positive result, whereas a negative result was indicated by the assay maintaining its brown color. The DNA biosensor was able to detect DNA at a concentration as low as 200 fg/μl, which is equivalent to 80 genomes/reaction. The specificity of the biosensor assay was 100% when it was evaluated with 172 bacterial strains. An integrated LAMP and probe-specific magnetogenosensor was successfully developed, promising simple and rapid visual detection in clinical diagnostics and service as a point-of-care device.
    Matched MeSH terms: Biosensing Techniques/methods*
  12. Current and future envision on developing biosensors aided by 2D molybdenum disulfide (MoS2) productions
    Dalila R N, Md Arshad MK, Gopinath SCB, Norhaimi WMW, Fathil MFM
    Biosens Bioelectron, 2019 May 01;132:248-264.
    PMID: 30878725 DOI: 10.1016/j.bios.2019.03.005
    Two-dimensional (2D) layered nanomaterials have triggered an intensive interest due to the fascinating physiochemical properties with the exceptional physical, optical and electrical characteristics that transpired from the quantum size effect of their ultra-thin structure. Among the family of 2D nanomaterials, molybdenum disulfide (MoS2) features distinct characteristics related to the existence of direct energy bandgap, which significantly lowers the leakage current and surpasses other 2D materials. In this overview, we expatiate the novel strategies to synthesize MoS2 that cover techniques such as liquid exfoliation, chemical vapour deposition, mechanical exfoliation, hydrothermal reaction, and Van Der Waal epitaxial growth on the substrate. We extend the discussion on the recent progress in biosensing applications of the produced MoS2, highlighting the important surface-to-volume of ultrathin MoS2 structure, which enhances the overall performance of the devices. Further, envisioned the missing piece with the current MoS2-based biosensors towards developing the future strategies.
    Matched MeSH terms: Biosensing Techniques/methods*
  13. A reduced graphene oxide-titanium dioxide nanocomposite based electrochemical aptasensor for rapid and sensitive detection of Salmonella enterica
    Muniandy S, Teh SJ, Appaturi JN, Thong KL, Lai CW, Ibrahim F, et al.
    Bioelectrochemistry, 2019 Jun;127:136-144.
    PMID: 30825657 DOI: 10.1016/j.bioelechem.2019.02.005
    Recent foodborne outbreaks in multiple locations necessitate the continuous development of highly sensitive and specific biosensors that offer rapid detection of foodborne biological hazards. This work focuses on the development of a reduced graphene oxide‑titanium dioxide (rGO-TiO2) nanocomposite based aptasensor to detect Salmonella enterica serovar Typhimurium. A label-free aptamer was immobilized on a rGO-TiO2 nanocomposite matrix through electrostatic interactions. The changes in electrical conductivity on the electrode surface were evaluated using electroanalytical methods. DNA aptamer adsorbed on the rGO-TiO2 surface bound to the bacterial cells at the electrode interface causing a physical barrier inhibiting the electron transfer. This interaction decreased the DPV signal of the electrode proportional to decreasing concentrations of the bacterial cells. The optimized aptasensor exhibited high sensitivity with a wide detection range (108 to 101 cfu mL-1), a low detection limit of 101 cfu mL-1 and good selectivity for Salmonella bacteria. This rGO-TiO2 aptasensor is an excellent biosensing platform that offers a reliable, rapid and sensitive alternative for foodborne pathogen detection.
    Matched MeSH terms: Biosensing Techniques/methods*
  14. Nanocrystalline cellulose decorated quantum dots based tyrosinase biosensor for phenol determination
    Manan FAA, Hong WW, Abdullah J, Yusof NA, Ahmad I
    Mater Sci Eng C Mater Biol Appl, 2019 Jun;99:37-46.
    PMID: 30889711 DOI: 10.1016/j.msec.2019.01.082
    Novel biosensor architecture based on nanocrystalline cellulose (NCC)/CdS quantum dots (QDs) nanocomposite was developed for phenol determination. This nanocomposite was prepared with slight modification of nanocrystalline cellulose (NCC) with cationic surfactant of cetyltriammonium bromide (CTAB) and further decorated with 3-mercaptopropionic acid (3-MPA) capped CdS QDs. The nanocomposite material was then employed as scaffold for immobilization of tyrosinase enzyme (Tyr). The electrocatalytic response of Tyr/CTAB-NCC/QDs nanocomposite towards phenol was evaluated using differential pulse voltammetry (DPV). The current response obtained is proportional to the concentration of phenol which attributed to the reduction of o-quinone produced at the surface of the modified electrode. Under the optimal conditions, the biosensor exhibits good linearity towards phenol in the concentration range of 5-40 μM (R2 = 0.9904) with sensitivity and limit of detection (LOD) of 0.078 μA/μM and 0.082 μM, respectively.
    Matched MeSH terms: Biosensing Techniques/methods*
  15. Gold interdigitated triple-microelectrodes for label-free prognosticative aptasensing of prostate cancer biomarker in serum
    Ibau C, Md Arshad MK, Gopinath SCB, Nuzaihan M N M, M Fathil MF, Estrela P
    Biosens Bioelectron, 2019 Jul 01;136:118-127.
    PMID: 31054519 DOI: 10.1016/j.bios.2019.04.048
    A simple, single-masked gold interdigitated triple-microelectrodes biosensor is presented by taking the advantage of an effective self-assembled monolayer (SAM) using an amino-silanization technique for the early detection of a prostate cancer's biomarker, the prostate-specific antigen (PSA). Unlike most interdigitated electrode biosensors, biorecognition happens in between the interdigitated electrodes, which enhances the sensitivity and limit of detection of the sensor. Using the Faradaic mode electrochemical impedance spectroscopy (EIS) technique to quantify the PSA antigen, the developed sensing platform demonstrates a logarithmic detection of PSA ranging from 0.5 ng/ml to 5000 ng/ml, an estimated LOD down to 0.51 ng/ml in the serum, and a good sensor's reproducibility. The sensor's detection range covers the clinical threshold value at 4 ng/ml and the crucial diagnosis 'grey zone' of 4-10 ng/ml of PSA in serum for an accurate cancer diagnosis. The selectivity test revealed an excellent discrimination of other competing proteins, with a recorded detection signals at 5 ng/ml PSA as high as 7-fold increase versus the human serum albumin (HSA) and 8-fold increase versus the human glandular kallikrein 2 (hK2). The stability test showed an acceptable stability of the aptasensor recorded at six (6) days before the detection signal started degrading below 10% of the peak detection value. The developed sensing scheme is proven to exhibit a great potential as a portable prostate cancer biosensor, also as a universal platform for bio-molecular sensing with the versatility to implement nanoparticles and other surface chemistry for various applications.
    Matched MeSH terms: Biosensing Techniques/methods*
  16. Current approaches for detection of human T-lymphotropic virus Type 1: A systematic review
    Fani M, Rezayi M, Meshkat Z, Rezaee SA, Makvandi M, Abouzari-Lotf E, et al.
    J Cell Physiol, 2019 08;234(8):12433-12441.
    PMID: 30633358 DOI: 10.1002/jcp.28087
    BACKGROUND: Human T-lymphotropic virus Type 1 (HTLV-1) is a retrovirus that is endemic in some regions of the world. It is known to cause several diseases like adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Serology and molecular methods have been used to detect this virus. Of these, enzyme-linked immunosorbent assay (ELISA) is used as a primary screening method and this is usually followed by western blotting (WB) and polymerase chain reaction (PCR) methods as confirmatory tests. We conducted a systematic review of the different techniques used in the diagnosis of HTLV-1 infection.

    MATERIALS AND METHODS: Our search was limited to original papers in the English language from 2010 to 2018 using several databases including Pubmed, Scopus, Google Scholar, Iranmedex, and Scientific Information Database. A manual search of references provided in the included papers was also performed.

    RESULTS: Of 101 electronically searched citations, 43 met the inclusion criteria. ELISA is commonly used for qualitative and screening detection, and WB and PCR techniques are used to confirm infection.

    CONCLUSION: Among all the reported methods for detection of HTLV-1, only serological and molecular tests are used as the most common technical assays for HTLV-1. The ELISA assay, without a confirmatory test, has several limitations and affect the accuracy of the results. Owing to the prevalence of HTLV-1 and limitations of the current detection methods, further evaluation of the accuracy of these methods is needed. There are new opportunities for applying novel technological advances in microfluidics, biosensors, and lab-on-a-chip systems to perform HTLV-1 diagnostics.

    Matched MeSH terms: Biosensing Techniques/methods
  17. Human papilloma virus DNA-biomarker analysis for cervical cancer: Signal enhancement by gold nanoparticle-coupled tetravalent streptavidin-biotin strategy
    Lv Q, Wang Y, Su C, Lakshmipriya T, Gopinath SCB, Pandian K, et al.
    Int J Biol Macromol, 2019 Aug 01;134:354-360.
    PMID: 31078598 DOI: 10.1016/j.ijbiomac.2019.05.044
    Human papillomavirus (HPV) is a double-standard DNA virus, as well as the source of infection to the mucous membrane. It is a sexually transmitted disease that brings the changes in the cervix cells. Oncogenes, E6 and E7 play a pivotal role in the HPV infection. Identifying these genes to detect HPV strains, especially a prevalent HPV16 strain, will bring a great impact. Among different sensing strategies for pathogens, the dielectric electrochemical biosensor shows the potential due to its higher sensitivity. In this research, HPV16-E7 DNA sequence was detected on the carbodiimidazole-modified interdigitated electrode (IDE) surface with the detection limit of 1 fM. To enhance the sensitivity, the target sequence was conjugated on gold nanoparticle (GNP) and attained detection to the level of 10 aM. This produced ~100 folds improvement in detecting HPV16-E7 gene and 4 folds increment in the current flow. The stability of HPV16-E7 DNA sequences on GNP was verified by the salt-induced GNP aggregation. The current system has shown the higher specificity by comparing against non-complementary and triple-mismatched DNA sequences of HPV16-E7. This demonstration in detecting HPV16-E7 using dielectric IDE sensing system with a higher sensitivity can be recommended for detecting a wide range of disease-causing DNA-markers.
    Matched MeSH terms: Biosensing Techniques/methods*
  18. Fulltext Effect of solution pH and adsorbent concentration on the sensing parameters of TGN-based electrochemical sensor
    Rahmani M, Ghafoorifard H, Afrang S, Ahmadi MT, Rahmani K, Ismail R
    IET Nanobiotechnol, 2019 Aug;13(6):584-592.
    PMID: 31432790 DOI: 10.1049/iet-nbt.2018.5288
    The response of trilayer graphene nanoribbon (TGN)-based ion-sensitive field-effect transistor (ISFET) to different pH solutions and adsorption effect on the sensing parameters are analytically studied in this research. The authors propose a TGN-based sensor to electrochemically detect pH. To this end, absorption effect on the sensing area in the form of carrier concentration, carrier velocity, and conductance variations are investigated. Also, the caused electrical response on TGN as a detection element is analytically proposed, in which significant current decrease of the sensor is observed after exposure to high pH values. In order to verify the accuracy of the model, it is compared with recent reports on pH sensors. The TGN-based pH sensor exposes higher current compared to that of carbon nanotube (CNT) counterpart for analogous ambient conditions. While, the comparative results demonstrate that the conductance of proposed model is lower than that of monolayer graphene-counterpart for equivalent pH values. The results confirm that the conductance of the sensor is decreased and Vg-min is obviously right-shifted by increasing value of pH. The authors demonstrate that although there is not the experimental evidence reported in the part of literature for TGN sensor, but the model can assist in comprehending experiments involving nanoscale pH sensors.
    Matched MeSH terms: Biosensing Techniques/methods*
  19. Multidimensional (0D-3D) nanostructures for lung cancer biomarker analysis: Comprehensive assessment on current diagnostics
    Ramanathan S, Gopinath SCB, Md Arshad MK, Poopalan P
    Biosens Bioelectron, 2019 Sep 15;141:111434.
    PMID: 31238281 DOI: 10.1016/j.bios.2019.111434
    The pragmatic outcome of a lung cancer diagnosis is closely interrelated in reducing the number of fatal death caused by the world's top cancerous disease. Regardless of the advancement made in understanding lung tumor, and its multimodal treatment, in general the percentage of survival remain low. Late diagnosis of a cancerous cell in patients is the major hurdle for the above circumstances. In the new era of a lung cancer diagnosis with low cost, portable and non-invasive clinical sampling, nanotechnology is at its inflection point where current researches focus on the implementation of biosensor conjugated nanomaterials for the generation of the ideal sensing. The present review encloses the superiority of nanomaterials from zero to three-dimensional nanostructures in its discrete and nanocomposites nanotopography on sensing lung cancer biomarkers. Recent researches conducted on definitive nanomaterials and nanocomposites at multiple dimension with distinctive physiochemical property were focused to subside the cases associated with lung cancer through the development of novel biosensors. The hurdles encountered in the recent research and future preference with prognostic clinical lung cancer diagnosis using multidimensional nanomaterials and its composites are presented.
    Matched MeSH terms: Biosensing Techniques/methods*
  20. Fulltext Aluminosilicate Nanocomposite on Genosensor: A Prospective Voltammetry Platform for Epidermal Growth Factor Receptor Mutant Analysis in Non-small Cell Lung Cancer
    Ramanathan S, Gopinath SCB, Arshad MKM, Poopalan P, Anbu P, Lakshmipriya T, et al.
    Sci Rep, 2019 11 19;9(1):17013.
    PMID: 31745155 DOI: 10.1038/s41598-019-53573-9
    Lung cancer is one of the most serious threats to human where 85% of lethal death caused by non-small cell lung cancer (NSCLC) induced by epidermal growth factor receptor (EGFR) mutation. The present research focuses in the development of efficient and effortless EGFR mutant detection strategy through high-performance and sensitive genosensor. The current amplified through 250 µm sized fingers between 100 µm aluminium electrodes indicates the voltammetry signal generated by means of the mutant DNA sequence hybridization. To enhance the DNA immobilization and hybridization, ∼25 nm sized aluminosilicate nanocomposite synthesized from the disposed joss fly ash was deposited on the gaps between aluminium electrodes. The probe, mutant (complementary), and wild (single-base pair mismatch) targets were designed precisely from the genomic sequences denote the detection of EGFR mutation. Fourier-transform Infrared Spectroscopy analysis was performed at every step of surface functionalization evidences the relevant chemical bonding of biomolecules on the genosensor as duplex DNA with peak response at 1150 cm-1 to 1650 cm-1. Genosensor depicts a sensitive EGFR mutation as it is able to detect apparently at 100 aM mutant against 1 µM DNA probe. The insignificant voltammetry signal generated with wild type strand emphasizes the specificity of genosensor in the detection of single base pair mismatch. The inefficiency of genosensor in detecting EGFR mutation in the absence of aluminosilicate nanocomposite implies the insensitivity of genosensing DNA hybridization and accentuates the significance of aluminosilicate. Based on the slope of the calibration curve, the attained sensitivity of aluminosilicate modified genosensor was 3.02E-4 A M-1. The detection limit of genosensor computed based on 3σ calculation, relative to the change of current proportional to the logarithm of mutant concentration is at 100 aM.
    Matched MeSH terms: Biosensing Techniques/methods*
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