Current Science and Technology

Applications of Nanomaterials for Biosensor Fabrication Based on Redox Enzyme and Protein: A Short Review

Nina Suhaity Azmi — 2023-06-15

Redox enzyme and protein modified biosensors are commercially triumphant bioelectronic devices used in the point-of-care analysis. The use of nanotechnology derived nanomaterials during enzyme immobilization creates a synergistic effect by integrating enzyme’s recognition and catalytic properties with the electronic properties of nanomaterials. This synergy improves the biosensor’s sensitivity, conductivity stability, surface-to-volume ratio, selectivity, detection limit and other analytical features. This critical review focuses on the redox enzymes and proteins most frequently used in glucose and hydrogen peroxide sensing, such as horseradish peroxidase (HRP), glucose oxidase (GOx), hemoglobin (HB), and cytochrome C (Cyt c). Besides, we evaluate the state of art of this approach, selection of nanomaterials, preparation and immobilization mechanisms, their role and sensing applications. Besides advantages, the discussions have discussed on the pressing challenges of developing these sensors. This review will guide the research community to develop rational and highly efficient nanomaterial immobilized biosensors.

A Review Study on the Potential of Microalgae Biomass Producing Biopolymer Material

Noormazlinah Ahmad — 2023-06-15

This review focuses on the potential of microalgae biomass in producing biopolymer materials. Microalgae have gained attention as a sustainable and renewable source of energy and other useful products such as biofuels, pharmaceuticals, and cosmetics. One promising application of microalgae is as a source of biopolymers, which can be used as a sustainable alternative to traditional petroleum-based plastics. The review is conducted through a comprehensive search of electronic databases, screening of relevant articles, and synthesis of information obtained from the selected studies. The review also critically evaluates the strengths and limitations of the existing research on the potential of microalgae biomass in producing biopolymer materials. The outcomes in this review highlights key findings related to the potential applications of microalgae biomass in producing biopolymers and identifies areas for future research. The conclusions and recommendations of this review are important for guiding the development of sustainable and environmentally friendly biopolymer materials.

On-Site Sequencing Of Sars-Cov-2 Genomes Identify Two Variant Of Concern Clusters In Pahang, Malaysia

Hajar Fauzan Ahmad — 2023-06-15

Timely variant identification is required in respond to effective public health measures. It has been demonstrated that comprehending genetic epidemiology can be aided by a combination of public health expertise and through viral genomic sequencing using Oxford Nanopore Technologies (ONT). The purpose of this study is to determine the utility of using Oxford Nanopore Sequencing to elucidate the genetic epidemiology in two significant clusters in Pahang, Malaysia. The combined oropharyngeal and nasopharyngeal swabs of clinical specimens from two significant clusters in Pahang, Malaysia, were retrieved for long-read sequencing. Results: We identify Beta and Delta variants as 2 variants of concern from our analysis. We found that the B.1.351 (ß) and B.1.617 (D) variants were responsible for the Taman Tanah Putih Baru and Pasar Kemunting clusters, respectively. In conclusion, ONT long-read sequencing tools offer a practical solution with a number of advantages. ONT devices are compact, affordable, and need little technical hands-on or laboratory equipment to prepare samples. They can also be used to quickly and adaptably execute sequencing analyses and to understand genomic epidemiology.

Trace elements in market vegetables of Kuantan, Pahang: Estimation of dietary exposure

JOO HUI TAY — 2023-06-15

A study was conducted to investigate the concentrations of seven essential elements: Copper (Cu), iodine (I), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se) and zinc (Zn) as well as three non-essential elements: Arsenic (As), cadmium (Cd) and lead (Pb) in nine ready-to-eat market vegetables collected from Kuantan, Pahang. Samples of vegetables were obtained from a local market, acid-digested with nitric acid and then analysed for elements using Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). The mean concentration of essential elements decreased in the following order: Mn>Zn>Mo>Cu>I>Ni>Se, with individual concentrations ranging from below detection limit (bdl) to 207 mg/kg dw. Cadmium, a non-essential element, was detected in 8 samples at a mean concentration of 0.06 mg/kg dw, while Pb and As were not detected (bdl) in all samples. The estimated daily dietary intake (EDI) as well as the potential health risk associated with vegetable consumption were calculated. Hazard quotient (HQ) values less than one were obtained for both children and adults, indicating that consumption of these vegetables poses low risk to health.

Enzymatic Analysis and Characterization of Bromelain from Two Varieties of Pineapple (Ananas comosus) Fruit and Stem Extracts

Aizi Nor Mazila Ramli — 2023-06-15

This study was designed to examine the presence of enzymatic activity of fruit and stem bromelain extracted from two varieties of pineapple (Ananas comosus): Morris and Sarawak. The bromelain crude extract obtained from fruits and stems were tested for their protein content via Bradford’s assay, and both crude extract from Morris variety showed the highest value. Further analysis was done to investigate the proteolytic activity of the crude fruit and stem bromelain, resulting in Morris variety having the highest activity for fruit bromelain, while Sarawak variety having the highest activity for stem bromelain. The Gelatin Digestion Unit (GDU) analysis performed revealed both fruit and stem bromelain from Morris variety exhibited the highest activity. Furthermore, the temperature optimization showed that both fruit bromelain of Morris and Sarawak varieties were optimum at 35 ℃, while stem bromelain from both pineapple varieties were optimum at 45 ℃. Meanwhile, the optimum value of the pH for Sarawak variety extract of fruit and stem bromelain were found at pH 5.6, while Morris variety were optimum at pH 6.6. These results indicated both varieties of pineapple extracts of fruits and stems were having bromelain enzyme that can be further developed for application at industrial level.

Phenothiazine-functionalized rGO for Electrochemical Capacitor

Kwok Feng Chong — 2023-06-15

The functionalization arose as a technique to improve the physicochemical properties of the reduced graphene oxide (rGO) and consequently enhance the supercapacitor performance. The functionalization compound, phenothiazine (PTZ) introduces nitrogen and sulfur heteroatoms into rGO via the one-pot hydrothermal method at different mass ratio produced PTZ-rGO 5 and PTZ-rGO 10. Incorporation of PTZ on the rGO sheets in PTZ-rGO 5 contributes to the high surface area (163.49 m² g⁻¹) and pore volume (0.3187 cm³ g⁻¹) properties. Contradictory, overloaded PTZ not only shows a lower reduction effect but also reduces the amount of PTZ functionalized in the PTZ-rGO 10 and consequently shows lower electrochemical performance. The excellent properties enable PTZ-rGO 5 enable it to achieve 119.5 F g⁻¹ at 0.5 A g⁻¹ for its specific capacitance and drive it to be the promising electrode material for supercapacitors.

In Vitro Safety & Quality Analysis on Three Species of Tongkat Ali Plants & Their In Vivo Elevation of Testosterone in Fowls

Tn Said Sharifah Aminah — 2023-06-15

Eurycoma longifolia, Polyathia bullata, and Stema tuberosa are three species of plants sharing the synonym of "Tongkat Ali" and commonly known as Tongkat Ali Putih, Tongkat Ali Hitam, and Tongkat Ali Merah, respectively. However, less study has been done on its effectiveness to increase testosterone by P. bullata and S. tuberosa compared to E. longifolia. In this study, all three types of Tongkat Ali were compared for their testosterone elevations in fowls. The roots of the plants were encapsulated and given to fowls. Before being tested on animals, the capsules' content was analyzed on a few safety and quality parameters, i.e., pH and moisture tests, heavy metal content, microbial load, and steroid presence. A total of 12 mg of each Tongkat Ali powdered material included in a capsule and given to 14 fowls for 30 days. The outcome showed an increase in testosterone in fowls with the highest value of 9.73 ± 1.20 nmol/L obtained by P. bullata, followed by E. longifolia and S. tuberosa, 7.70 ± 0.59 nmol/L, and 6.25 ± 0.70 nmol/L, respectively compared to the control of only 4.08 ± 0.85 nmol/L. The results showed that P. bullata and S. tuberosa were safe to consume (in vitro) and able to increase testosterone level in the fowls (in vivo). Thus, it also provide added information on the less studied Tongkat Ali plants and their potential as an aphrodisiac plants.

Polyvinylidene Fluoride (PVDF) / Poly (Ether Sulfones) (PES) Blend Membrane For CO2/CH4 Separation

Q Ramzi — 2023-06-15

In this study, a combination of Polyvinylidene fluoride (PVDF) and Poly (ether sulfones) (PES) blend membrane and DMF as solvent component was developed to evaluate the CO₂ and CH₄separation performance. The gas permeation test was thereafter conducted on the membrane produced. The separation through a membrane works on the theory of permeation based on permeability and selectivity. These two important values were estimated using a set of analytical functions. The membranes produced was then characterized using scanning electron microscopy (SEM) and the Fourier Transform Infrared Spectroscopy (FTIR). The result obtained revealed that a higher permeability for the CO₂and CH₄ gases when the blending ratio of membrane and solvent of PVDF:PES:DMF/ 5:15:80 were applied. Moreover, the selectivity results showed that the use of the blending ratio of PVDF:PES:DMF/ 20:0:80 produce the highest selectivity (1.3086 GPU) while blending ratio of PVDF:PES:DMF/ 10:10:80 exhibited the least selectivity. In addition, the morphological elucidation revealed the presence of pores for every cross-section composite membrane and this aids the permeability properties of the membrane aggregates at different blending ratio. Also, the FTIR results showed nearly similar functional group characteristics.