Effect of pH and salt concentration on protein solubility of slaughtered and non-slaughtered broiler chicken meat

This study examined the influence of pH and salt concentration on the protein solubility of slaughtered and non-slaughtered broiler chicken meat. Three types of salt (NaCl, Na2SO4, and (NH4)2SO4), five different pH levels (5.0, 6.0, 7.0, 8.0 and 9.0) and five salt concentrations (0.4, 0.8, 1.2, 1.6, and 2.0 M) were examined. Each type of salt showed distinctive activities for slaughtered and non-slaughtered meat protein solubility. Soluble protein concentration increased as pH increased (p<0.05) from pH5.0 to 8.0 and decreased from pH8.0 to 9.0. It was also observed that protein solubility increased as the salt concentration increased. Protein solubility significantly increased (p<0.05) in the non-slaughtered meat compared to the slaughtered meat at pH8.0 for Na2SO4 at 1.2 M

Reviewed immunosensor format using nanomaterial for tungro virus detection

Recently, nanomaterial based biosensor application has drawn a lot attention among researchers because of specialty to enhance the sensor signal for increasing the sensitivity for detecting and identification of pathogen, viruses and toxic compound in controlling plant disease outbreak effectively. Rice tungro disease (RTD) causes a major problem in rice production and also will effect in the economic loss in the country. Therefore, early detection system is needed to monitor the disease at the early stage of the infection for preventing the disease outbreak in planting area. Lastly, this paper will discuss the current findings in rapid diagnostics using immunosensors technologies with nanomaterial application in enhancing the sensor signal for increasing the detection sensitivity

Gold nanoparticle sensor for the visual detection of pork adulteration in meatball formulation.

We visually identify pork adulteration in beef and chicken meatball preparations using 20 nm gold nanoparticles (GNPs) as colorimetric sensors. Meatball is a popular food in certain Asian and European countries. Verification of pork adulteration in meatball is necessary to meet the Halal and Kosher food standards. Twenty nm GNPs change color from pinkish-red to gray-purple, and their absorption peak at 525 nm is red-shifted by 30–50 nm in 3 mM phosphate buffer saline (PBS). Adsorption of single-stranded DNA protects the particles against salt-induced aggregation. Mixing and annealing of a 25-nucleotide (nt) single-stranded (ss) DNA probe with denatured DNA of different meatballs differentiated well between perfectly matched and mismatch hybridization at a critical annealing temperature. The probes become available in nonpork DNA containing vials due to mismatches and interact with GNPs to protect them from salt-induced aggregation. Whereas, all the pork containing vials, either in pure and mixed forms, consumed the probes totally by perfect hybridization and turned into grey, indicating aggregation. This is clearly reflected by a well-defined red-shift of the absorption peak and significantly increased absorbance in 550–800 nm regimes. This label-free low-cost assay should find applications in food analysis, genetic screening, and homology studies

Comparative study between ELISA and surface plasmon resonance (SPR) for rice tungro disease detection

Rice tungro disease (tungro) is one of the most damaging diseases of rice in South and Southeast Asia. This disease is caused by dual infections from rice tungro bacilliform virus (RTBV) and rice tungro spherical virus (RTSV). Both are transmitted by green leaf hoppers (GLH).This disease make serious loss of income to farmers when their crops are affected with an approximately 5-10% annual losses of rice yield in Asia was affected by rice tungro disease. This disease contributes to serious loss of income to farmers and also accounts for an approximately 5-10% annual loss of rice yield in Asia.Immunosensors based Surface Plasmon Resonance (SPR) and ELISA that used specific antigen-antibody reaction format have become a promising tool for the quantification of viruses. However both method need to compare which is to be used to determine the antigen with highly sensitive, specific, rapid, and label free detection for the analysis

A novel disposable biosensor based on SiNWs/AuNPs modified-screen printed electrode for dengue virus DNA oligomer detection

In this study, a disposable screen-printed gold electrode (SPGE) utilized of silicon nanowires (SiNWs) and gold nanoparticles as sensing material was fabricated for detection of DNA oligomers related to dengue virus. Firstly, SiNWs/AuNPs-SPGE was developed by the dispersion of SiNWs in 3-Aminopropyltriethoxysilane (APTES, 0.5 %) onto bare SPGE. Secondly, the AuNPs decoration on SiNWs-SPGE surface was functionalized using dithiopropionic acid (DTPA) through a self-assembly monolayer (SAM) technique. The electrochemical response of methylene blue (MB) as a redox indicator towards synthetic DNA oligomer after hybridization on SiNWs/AuNPs-SPGE was recorded by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The results demonstrated that the reduction peak current of MB was significantly decreased after DNA hybridization process. In addition, the developed biosensor showed a good storage stability and could achieve a linear range of 1.0 × 10-11-1.0 × 10-7 M (R= 0.98) with the detection limit of 1.63× 10-12 M

Top-down fabrication of silicon nanowire sensor using electron beam and optical mixed lithography

The realization of reliable nanobiosensor devices requires the improvement of fabrication techniques to form the nanometer-sized structures and patterns, which were used to attach nano materials such as DNA for the device elements. This study demonstrates the sensitivity of silicon nanowires (SiNWs) as a sensing element in sensor application. Starting with silicon on insulator (SOI) material, the SiNWs with <100nm in width were fabricated using electron beam lithography combined with conventional CMOS process. Different numbers of SiNWs which are single, 10 arrays of nanowires and 20 arrays of nanowires were developed. Subsequently, the two metal electrodes which are designated as source (S) and drain (D) were fabricated on top of individual SiNWs using optical lithography process. Optical and electrical characteristic have been proposed to verify the outcome of the fabricated structures. One major part is to observe the SiNWs optically in order to meet the nano-scale variation by using High Power Microscope (HPM) inspection and Field Emission Scanning Electron Microscope (FESEM) imaging. Finally, the samples will be tested electrically using I-V measurement system. The results show that device with single SiNW with 60nm in width give the highest resistivity value due to surface to volume ratio

Sharp edges schottky contact electric field simulation

This paper reports investigation on effect of adding sharp edges to Schottky contact. Few studies suggested that sharp edge nanostructures produces high electric field which subsequently improve gas sensing performance on reversed biased mode. Three different shapes: circular-, hexagon- and star-shape were modeled by using COMSOL Multiphysics. The study on effects of different sizes sharp edges Schottky contact also reported. Electric field was observed and it shows that star-shape yields highest summation of electric field 2.79 x 109 V/m and lowest electric field observed at circular-shape 7 x 107 V/m. The results also revealed that distance of sharp edges from substrate edge affects the magnitude of electric field

Design and fabrication of silicon nanowire based sensor

This paper reports the process development of silicon nanowires sensor requires both the fabrication of nanoscale diameter wires and standard integration to CMOS process. By using silicon-on-insulator (SOI) wafer as a starting material, the nanowires is fabricated using a top-down approach which involved Scanning Electron Microscope based Electron Beam Lithography method. The silicon nanowires are well developed with the smallest dimension is 65nm in width. The effect of line width and exposure dose on the pattern structure is investigated experimentally using the negative photoresist ma-N2403 for EBL. The exposure doses for the resist layer are varied in the range of 50µC/cm2 to 180µC/cm2 at 20 kV accelerating voltage with a beam current of 0.075nA. The nanowires resist masks are well developed with dimension less than 100 nm in width for the dose exposure parameters of 80µC/cm2, 100µC/cm2 and 120µC/cm2. Subsequently, the two metal electrodes which are designated as source and drain are fabricated on top of individual nanowire using conventional lithography process. Morphological, electrical and chemical characteristics have been proposed to verify the outcome of the fabricated device. Finally, the fabricated device is performed as pH level detection. Three types of standard aqueous pH buffer buffer solutions which are pH 4, pH 7 and pH 10 are used to test the electrical response of the device. The SiNWs sensor show the highest resistance value for pH 4 and the lowest resistance value for pH 10. In terms of sensitivity, the device with smaller nanowire is found to be more sensitive than larger nanowire as a result of the high surface-to-volume ratio

Performance comparison of image normalisation method for DNA microarray data

Normalisation is a process of removing systematic variation that affects measured gene expression levels in microarray experiment. The purpose is to get a more accurate DNA microarray result by deleting the systematic errors that may have occurred when making the DNA microarray slid. In this paper, four normalisation methods of Global, Lowess, Quantile and Print-tip are discussed, tested and their final results compared in the form of Matrixes and graphs. Ideal and real microarray slides have been used for this project. It was found that the Print-tip normalisation method showed the closest results to the real result for an ideal microarray slide and it has a straight median line final graph. The Print-tip normalisation method uses more than one normalization factor that is divided among intervals which are dependent on the values of the addition of red and green logarithm