Pembentukan Kaedah Pengesan Racun Makhluk Perosak Menggunakan Teknik Elektrod Enzim dan Enzim Imunoasai

Kaedah elektrod enzim dan kaedah enzirn imunoasai telah dibentuk untuk menganggarkan kepekatan racun rnakhluk perosak dalam pemonitoran alam sekitar. Enzim Asetilkolinesterase (AchE) dan Kolin Oksidase (ChO) yang disekatgerak pada rnernbran elektrod oksigen secara fizikal, taut silang dan pemerangkapan gelatin telah digunakan sebagai elektrod enzim. Sekatgerak enzim secara taut silang didapati paling sensitif untuk penentuan racun makhluk perosak. Racun Paration, Karbofuran dan asid 2,4-Dwiklorofenoksi asetik (2,4-D) telah digunakan untuk menguji darjah kesensitifan elektrod enzirn. Elektrod enzim dengan enzim yang disekatgerak secara taut silang menunjukkan separuh perencatan maksimum (I₅₀) bagi Paration ialah 0.00001 µg/L dan 0.0002 µg/L bagi Karbofuran. Tiada kesan perencatan bagi racun 2,4-D. Julat kepekatan racun yang boleh dikesan oleh elektrod enzim adalah 0.00001-0.0001 µg/L bagi Paration dan 0.00001-0.001µg/L bagi Karbofuran. 2-amino-2-(hidroksimetil)-1,3-propandiol (2- PAM) pada kepekatan 1 x 10-3M didapati sesuai digunakan sebagai bahan pengaktif bagi enzim pada elektrod yang telah didedahkan kepada racun makhluk perosa

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

Detection of malachite green and leuco-malachite green in fishery industry

This article summarises the current methods for total malachite green (MG) detectionwhich is known as a sum of MG and leuco-malachite green (LMG) that has been used extensively in aquaculture as fungicide, dye color in textile and other purposes in food industries. LMG is a reducing form of MG, where the MG is easily reduced due to the photo-oxidative de-methylation process. Nevertheless, the use of MG had become an issue due to its toxicity effects. Many analytical instruments such as HPLC, LC-MS/MS, GC-MS, and spectrometry have been widely used for detection of MG. However, these methods require long time sample preparation and analysis, expensive, use hazardous reagents and indirect measurements. Hence, other analytical methods which are more sensitive, safe, rapid, inexpensive andportable are required. Alternatively, biosensors promise a more sensitive and rapid detection method for MG and LMG

Kajian potensi ekstrak bilberi sebagai penunjuk pH untuk memantau kesegaran makanan secara kromametri

Penunjuk pH sebagai suatu pendekatan untuk memantau kualiti atau kesegaran makanan semasa telah mendapat perhatian industri pembungkusan makanan. Penggunaan sumber semula jadi pigmen tumbuhan terutamanya daripada buah-buahan dan sayur-sayuran menjadi pilihan para pengguna untuk menggantikan pewarna sintetik dalam memastikan keselamatan makanan yang diambil setiap hari. Dalam kajian ini, ekstrak daripada bilberi telah digunakan sebagai pewarna sensitif pH. Perubahan warna sampel dikaji secara terperinci melalui kaedah kromametri dan juga kaedah spektrofotometri ultra-lembayung nampak. Warna merah terang terhasil dalam pH berasid, merah pudar pada neutral dan magenta ke kuning dalam pH beralkali. Keputusan kajian kromametri menunjukkan bahawa ekstrak bilberi berupaya mempamerkan perubahan warna yang jelas terhadap perubahan pH, iaitu terdapat perubahan nilai warna a* yang menyumbang kepada perubahan yang bererti dalam perbezaan warna keseluruhan (ΔE*). Nilai ΔE* juga ditentukan wujud hubungan linear dan kuantitatif terhadap julat pH tertentu. Oleh yang demikian, ekstrak bilberi didapati berpotensi sebagai bahan sensor untuk pH dalam membangunkan satu sensor pH bagi memantau kesegaran makanan terutamanya hasilan laut berbungkus memandangkan tahap kerosakan produk tersebut berkait rapat dengan perubahan pH ke arah alkali

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

Determination of set potential voltages for cucumber mosaic virus detection using screen printed carbon electrode

Cucumber Mosaic Virus (CMV) is a most dangerous pathogen among the cucurbit plant which it striking cucumbers, zucchinis, squashes, watermelons but it also striking to non-cucurbit such as peppers, tobaccos, celeries, beans and tomatoes. Symptoms shown by this virus when they starting to strike are very significant and at the end can kill the hosts they infected. In order to detect these viruses, biosensor such as screen-printed carbon electrode (SPCE) is developed and fixes a set potential voltage is defined using Chronoamperometry (CM) immunosensor technique. For short introduction, CM is a process which is a constant applied potential voltage between the working and reference electrode is maintained in order to create an electrons transfer for the oxidation or reduction species taking place at the surface of working electrode is measured and in this manuscript, complete details about measurement were used to finding the stable set potential voltages will be pointed out

Immunosensor development formatting for tungro disease detection using nano-gold antibody particles application

The plant disease such as Rice tungro disease (RTD) becomes a major problem in rice production and also will effect in the economy loss in the country. Therefore, to tackle this problem at early stages, the immunosensor application is a most reliable sensor nowadays because of advantages towards detecting biological molecule. Thus, in order to deal with immunosensor development, it can be done by undergoing the formation of immunosensor format on screen-printed carbon electrode (SPCE). Results can be elaborated with the potential applications to detect the viruses

Determination of fixed-potential selection using chronoamperometry analysis by screen-printed carbon electrode for rice tungro bacilliform virus (RTBV) detection

This paper describes the analysis for the determination of fixed-potential selection using chronoamperometry technique for the detection of rice tungro bacilliform virus (RTBV). RTBV is one of the viruses that cause Tungro disease in rice plantation where the epidemic has been reported since the mid-1960s. Thus immuno-biosensor developed here can replace traditional and conventional analytical systems. One of the important steps to develop immunosensor is to determine the best potential to use in this system to indicate high percentage of active area in conducting electron and it can be used as the best potential for future immunosensor development

A carbon dots based fluorescence sensing for the determination of Escherichia coli O157:H7

Sensing founded on fluorescence quenching involving carbon dots (CDs) and gold nanoparticles (AuNPs) for the determination of Escherichia coli (E. coli) O157:H7 has been explored. CDs act as the fluorophore, while AuNPs as the quencher. Target oligos have been utilized to establish distance between CDs and AuNPs nanoparticles in close proximity. At excitation/emission wavelength of 340 nm/450 nm, respectively, the net CDs fluorescence quenching increased proportionally with increasing viscosity of the target oligos. A linear correlation was found between the fluorescence quenching of CDs and the logarithm concentration of target oligos in the series of 0.01–200 nM (slope = 675.6, R2 = 0.992) with the detection limit (LOD) of 1.03 ± 3.54 nM. The proposed method was utilized for verification of selectivity and specificity towards different oligonucleotide sequence and bacteria strain with satisfactory results

Immunosensing of Aflatoxin B1 and Ochratoxin A on a Portable Device as Point-of-Care

Aflatoxin B1 (AFB1) and ochratoxin A (OTA) are potent mycotoxins produced by the fungal genus Aspergillus. Their occurrence in grain corn is alarming hence the need for rapid on-site detection. An immuno-based biosensor technique for detection of the aforementioned toxins is described here. Highly specific in-house polyclonal antibodies against AFB1 and OTA were employed as bioreceptors in a label-free electrochemical biosensor; immobilized on modified screen-printed carbon electrodes (SPCEs). The immuno-functionalized SPCEs were first characterized on a laboratory electrochemical workstation for proof-on-concept study using differential pulse voltammetry (DPV) electrochemical technique. An Android-based device is improvised as a portable electrochemical reader integrated with internet of thing (IoT) features which include cloud server and a dedicated website. Sensitivity achieved by the modified SPCEs on the portable device is superior compared to enzyme-linked immunosorbent assay (ELISA) method and lab-based electrochemical workstation. The miniaturized biosensor system has been successfully tested on cornfield for in-situ mycotoxins detection with simple sample extraction. Analysis performed on twenty samples were validated using chromatographic analysis. This biosensor-IoT system offers a potential application for real-time detection and the portable reader serves as an excellent tool for point-of-care in routine monitoring of harmful mycotoxins