Md. Biplob Hossain; Mehedi Hassan; Lway Faisal Abdulrazak; Md. Masud Rana; Md. Mohaiminul Islam; M. Saifur Rahman
Abstract
In this letter, a surface plasmon resonance (SPR) biosensor is numerically investigated that used Graphene-MoS2-Au-TiO2-SiO2 hybrid structure for the detection of formalin. This developed sensor sensed the presence of formalin based on attenuated total reflection (ATR) method by observing the change ...
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In this letter, a surface plasmon resonance (SPR) biosensor is numerically investigated that used Graphene-MoS2-Au-TiO2-SiO2 hybrid structure for the detection of formalin. This developed sensor sensed the presence of formalin based on attenuated total reflection (ATR) method by observing the change of “surface plasmon resonance (SPR) angle versus the change of minimum reflectance” attributor and “the surface plasmon resonance frequency (SPRF) versus maximum transmittance” attributor. Chitosan is used as probe legend to perform the particular reaction with the formalin (formaldehyde) as target legend. Here, graphene as well as MoS2 are used as biomolecular recognition element (BRE), TiO2-SiO2 bilayer as the improvement of sensitivity and Gold (Au) as the sharp SPR curve. Numerical results are appeared that the variation of SPRF and SPR angle for improper sensing of formalin is quite negligible that confirms the absence of formalin whereas for proper sensing is considerably countable that confirms the presence of formalin. It is also shown that the sensitivity of conventional SPR sensor is 70.74% and the graphene–MoS2-based sensor is enhanced to 77% with respect conventional SPR sensor. The sensitivity is further enhanced to 79 % by including TiO2–SiO2 composite layer with respect to conventional SPR sensor. At the end of this letter, a comparative study of the sensitivity of the proposed work with the existing works is discussed. Copyright © VBRI Press.
Yilkal D. Sintayehu; H. C. Ananda Murthy
Abstract
The involvement and development of intelligent polymers in enzymes as a catalyst have been interesting to develop processes that are environmentally benign, energy efficient, and selective towards their specific molecular applications. Polypyrrole based enzyme nanocomposites represents a continuous considerable ...
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The involvement and development of intelligent polymers in enzymes as a catalyst have been interesting to develop processes that are environmentally benign, energy efficient, and selective towards their specific molecular applications. Polypyrrole based enzyme nanocomposites represents a continuous considerable redox organic polymer that have been increased in electromechanical devices in advance for surface functionalization. This review addresses the fundamental concepts of polypyrole and its composites role for enzyme immobilizing functioning and its bio functional bioelectrocatalytic system operating principle in biosensor and biofuel cells as well as its involvement in electron transfer mechanism as a bio electrode to create an advanced bioelectronics device from power generating system to extreme analyte detecting system. Copyright © VBRI Press.
Suman Singh; D. V. S. Jain; M. L. Singla
Abstract
This manuscript presents in-situ electrochemical synthesis of Prussian Blue-gold nanoparticles (PB- AuNPs) composite for application in hydrogen peroxide (H2O2) biosensor. The SEM image clearly showed the presence of AuNPs of size in range of 50 to 200 nm spread on PB matrix. UV-Visible spectra showed ...
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This manuscript presents in-situ electrochemical synthesis of Prussian Blue-gold nanoparticles (PB- AuNPs) composite for application in hydrogen peroxide (H2O2) biosensor. The SEM image clearly showed the presence of AuNPs of size in range of 50 to 200 nm spread on PB matrix. UV-Visible spectra showed absorbance peak at 530 nm corresponding to AuNPs and a hump in 690-740 nm region for PB, confirming the synthesis of composite. The cyclic voltammetry (CV) showed the surface coverage of 3.65 x 10 -9 mol/cm 2 for pure PB film and 4.33 x 10 -9 mol/cm 2 for PB-AuNPs film, with diffusion coefficient of 1.19 x 10 -9 cm 2 /s, and 5.64 x 10 -9 cm 2 /s respectively. The film thickness is found to be 2.4 x 10 -12 cm for PB and 2.9 x 10 -12 cm for PB-AuNPs composite. The concentration of redox active centers (Fe +3/+2 ) is 3.5 moles/cm 3 for ITO/PB and 4.1 moles/cm 3 for ITO/PB-AuNPs respectively. The CV of ITO/PB showed one redox couple at 0.118 V and 0.215 V, whereas with ITO/PB-AuNPs electrode, two sets of well-defined redox peaks; (i) 0.095 V & 0.135 V and (ii) 0.74 V & 0.78 V were obtained. The faradic current obtained with ITO/PB was 3.6 x 10 -3 A and 7.3 x 10 -3 A for ITO/PB-AuNPs composite film, respectively. The faradic current was almost double in presence of gold nanoparticles, as compared to pure PB. For H2O2 biosensor, the horse radish peroxidase (HRP) was immobilized on composite film and was used for H2O2 detection. The linearity was obtained from 10 to 90 nM, with sensitivity of 0.73µA/nM and the apparent Km value was 45 nM. The response time of reported biosensor is 20 sec and is stable for about three months.
Keisham Radhapyari; Raju Khan
Abstract
Electrochemical biosensor is an effective tool for pharmaceutical analysis due to its simplicity, specificity, sensitivity, fast, cost-effective and repetitive measurements with miniaturized and portable devices. The paper illustrates the detail methodology for development of an amperometric biosensor ...
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Electrochemical biosensor is an effective tool for pharmaceutical analysis due to its simplicity, specificity, sensitivity, fast, cost-effective and repetitive measurements with miniaturized and portable devices. The paper illustrates the detail methodology for development of an amperometric biosensor based on polyaniline-gold nanocomposite film modified horseradish peroxidase for anticancer drug gemcitabine in bulk and in parenteral formulation. Scanning Electron Microscopy, Cyclic Voltammetry, Fourier Transform Infra Red Spectroscopy and Electrochemical Impedance Spectroscopic studies of the electrodes and after immobilizing of HRP shows the successful formation of a selectivity of the electrode. The proposed polyaniline-gold nano-composite based biosensor allow quantitation over the range 0.10 to 1.10 ngmL −1 with detection limit of 0.031 ngmL −1 , biosensor sensitivity of 2.934 µAng mL -1 has distinct advantages over other existing methods. Precision and accuracy were also checked and were within the limits. The procedure has been applied to the assay of the drug in dosage form with mean percentage recoveries of 99.00±0.08%. The suggested biosensor method can be successfully applied to the detection and determination of anticancer drug gemcitabine in different drug formulations.
Bhavani Prasad Nenavathu; Raj Kumar Dutta
Abstract
Semiconductor nanoparticles (NPs) have attracted much attention as a new class of fluorescent probe for many biological applications including biosensors for glucose, cholesterol, cysteine etc., which were based on their size dependent unique electrical and photophysical properties. One of the major ...
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Semiconductor nanoparticles (NPs) have attracted much attention as a new class of fluorescent probe for many biological applications including biosensors for glucose, cholesterol, cysteine etc., which were based on their size dependent unique electrical and photophysical properties. One of the major challenges in fabricating nanomaterial based biosensor is conjugation of a suitable compound to quantum dots which is preferably selective to the analyte of interest. Here we report our studies on synthesis, characterization and application of jack bean meal urease immobilized on CdS quantum dots (QDs) for sensing of urea. The CdS QDs were synthesized by chemical precipitation method using Mercaptoacetic acid (MAA) for controlling size as well as for imparting functional group for conjugating urease. The urease immobilize on MAA capped CdS nanoparticle was characterized by an array of techniques, like, UV- visible, Fluorescence, XRD, FT-IR and SEM EDAX. The detection capability of urea was studied by fluorescence spectroscopy at an excitation wavelength of λex = 430 nm and emission wavelength of λem= 546 nm. This method was capable to detect urea in the concentration range of 0.1 µM to 1 mM.
Ravindra P. Singh; Da-Yeon Kang; Jeong-Woo Choi
Abstract
PANi/ClO4 doped films were developed electrochemically to immobilize DNA as biosensing platform to detect sanguinarine from adulterated mustard oils. The principle of technique was based on the interaction/intercalation of sanguinarine with dsDNA using electrochemical method. Further, it was suggested ...
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PANi/ClO4 doped films were developed electrochemically to immobilize DNA as biosensing platform to detect sanguinarine from adulterated mustard oils. The principle of technique was based on the interaction/intercalation of sanguinarine with dsDNA using electrochemical method. Further, it was suggested that sanguinarine intercalates with DNA strands forming complexes, results in the decrease of redox peak currents. In addition, the decrease of the peak current is proportional to the concentration of sanguinarine. The results based on the voltammetric signals decreased in concomitant increase of sanguinarine concentrations due to base pairing in dsDNA. The bioelectrode exhibited the detection limits 2–64 μM. The recovery experiment results found between 89% and 121% from spiked edible mustard oil sources. The correlation found between the current vs. concentration of SA with a correlation coefficient of (r 2 ) of 0.995 at 95% confidence limit. UV–VIS, CV, DPV, AFM, and SEM. characterized the bioelectrodes. Thus, the proposed electrochemical DNA biosensor detected SA and promising for real-time analysis of small molecules of environmental interest.
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