Enhanced uric acid detection using functionalized multi-walled carbon nanotube/AgNi nanocomposites: A comparative study on screen-printed carbon electrode (SPCE) and fabric-based biosensors Yuan Alfinsyah Sihombing, Uperianti, Rizky Indah Sari, Beni Rio Hermanto, Murni Handayani, Samuel Priyantoro Kusumocahyo, Mokhamad Fakhrul Ulum, Rikson Siburian, Cepi Kurniawan, Nuni Widiarti, Yeni Wahyuni Hartati, Isa Anshori Sensors and Actuators Reports, 2024 In the development of biosensors, it is essential to have sensors that provide rapid responses, exhibit high sensitivity and selectivity, and are non-invasive, such as screen-printed carbon electrode-based biosensors. In this study, SPCE-based and fabric-based biosensors were fabricated by modifying the working electrode (WE) surface using functionalized Multi-walled Carbon Nanotube/AgNi nanocomposites (f-MWCNT/AgNi) to enhance the biosensor's performance in detecting uric acid (UA). The successful synthesis of the f-MWCNT/AgNi nanomaterial was confirmed through UV–Vis, Raman, SEM–EDX, and XRD analyses. The f-MWCNT/AgNi nanomaterials were deposited on the WE surface using drop-casting. Subsequently, electrochemical characteristic tests and UA detection performance were conducted using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. The DPV curves revealed sensitivities of 27.699 μA/mM and 4.638 μA/mM for SPCE-based and fabric-based electrodes, respectively. The limit of detection (LOD) values for UA detection were 0.024 and 0.017 mM, with linearity (R2) 0.997 and 0.999 observed within the linear ranges of 0.05–1.00 and 1.0–5.0 mM, respectively. Both biosensors exhibited strong selectivity for UA against other components, including ascorbic acid, glucose, lactic acid, and ethanol. Based on these parameter values, f-MWCNT/AgNi-modified SPCE and fabric-based electrodes can be promoted as biosensors for uric acid detection.
Evaluation of electrodeposition synthesis of gold nanodendrite on screen-printed carbon electrode for nonenzymatic ascorbic acid sensor Eduardus Ariasena, Aldyla Nisa Raditya, Nadia Salsabila, Geolita Ihsantia Ning Asih, Uperianti, Rizky Indah Sari, Murni Handayani, Rikson Siburian, Cepi Kurniawan, Nuni Widiarti, Irkham, Yeni Wahyuni Hartati, Isa Anshori Scientific Reports, 2024 Gold nanodendrite (AuND) is a type of gold nanoparticles with dendritic or branching structures that offers advantages such as large surface area and high conductivity to improve electrocatalytic performance of electrochemical sensors. AuND structures can be synthesized using electrodeposition method utilizing cysteine as growth directing agent. This method can simultaneously synthesize and integrate the gold nanostructures on the surface of the electrode. We conducted a comprehensive study on the synthesis of AuND on screen-printed carbon electrode (SPCE)-based working electrode, focusing on the optimization of electrodeposition parameters, such as applied potential, precursor solution concentration, and deposition time. The measured surface oxide reduction peak current and electrochemical surface area from cyclic voltammogram were used as the optimization indicators. We confirmed the growth of dendritic gold nanostructures across the carbon electrode surface based on FESEM, EDS, and XRD characterizations. We applied the SPCE/AuND electrode as a nonenzymatic sensor on ascorbic acid (AA) and obtained detection limit of 16.8 μM, quantification limit of 51.0 μM, sensitivity of 0.0629 μA μM −1 , and linear range of 180–2700 μM (R 2 value = 0.9909). Selectivity test of this electrode against several interferences, such as uric acid, dopamine, glucose, and urea, also shows good response in AA detection.
Science Teachers’ Instructional Practices: A Need Analysis for Preparing Integrated STEM Practices through Scientist-Teacher-Student Partnership Ismail, Mohamad Hisyam, Mohd Fadzil, Hidayah, Mat Salleh, Muhamad Furkan, Mohd Saat, Rohaida, Kurniawan, Cepi, et al. Asian Journal of University Education, 2024 The declining number of students choosing STEM subjects and careers in Malaysia has raised concern about the education system’s ability to produce sufficient human development for sound national development. The teaching approach used by the teachers to integrate STEM in the classroom practices is often claimed as one of the main determining factors contributing to this issue. Concerning this issue, this qualitative study aimed to investigate science teachers’ practices in integrating STEM in their classrooms. The interviews were conducted with six science teachers from various secondary schools in Malaysia who represented three major disciplines (Biology, Physics, and Chemistry). The purposive sampling technique was employed to select six science teachers who were involved in this study. As part of a larger study, the objectives of this study were mainly focused on exploring the instructional practices by the teachers to integrate STEM content in their classrooms, where constant comparative methods were used for data analysis. Three themes emerged from the interviews, namely, (1) instructional strategy, (2) elements of STEM, and (3) issues of the practice. The study found that all science teachers have different strategies to integrate STEM into their classrooms, such as inquiry-based and problem-based learning. To integrate STEM disciplines, the teachers are mostly focused on embedding STEM skills through hands-on activity or highlighting the real-life applications of the STEM concepts during the lesson. Less emphasis is given on connecting concepts of different disciplines during teaching and learning, and teacher-driven activities were among the issues discovered in teachers’ instructional practices. Despite their efforts, they admitted that they still lack the skills to integrate STEM and need help from experts, mainly from STEM practitioners like scientists and engineers. The study concludes that science teachers need to improve their delivery of STEM subjects more effectively. Moreover, the findings could assist stakeholders, particularly teacher training institutions, in re-assessing their education programs for current demand.
Synthesis and Characterization of A Fascinating Coordination Polymer Metal-Organic Framework Featuring Cobalt (II) and 4,4'-Bipyridine Cepi Kurniawan Molekul, 2024 This investigation delineates the fabrication, comprehensive characterization, and electrochemical evaluation of a one-dimensional Cobalt-based Metal-Organic Framework (Co-MOFs), constructed from 4,4’-Bipyridine ligands and Cobalt (II) ions. The study aimed to perfect the synthesis protocol, elucidate the structural and compositional attributes of the resultant MOF, and probe its electrochemical performance. Utilizing the reflux method, renowned for its efficacy and eco-compatibility, we synthesized the MOF and affirmed its formation through a suite of analytical techniques, including Infrared (IR) spectroscopy, Ultraviolet-Visible (UV-Vis) spectroscopy, Atomic Absorption Spectroscopy (AAS), and electrical conductivity measurements. The synthesized Co-MOFs, chemically notated as [Co2(4,4'-bpy)2(SO4)(H2O)2]SO4·H2O, manifested as a one-dimensional coordination polymer. X-ray Diffraction (XRD) analysis unveiled its monoclinic crystallinity within the C2 space group. Electrochemical characterization uncovered a reversible redox system, evidenced by a robust peak current ratio (IPa/IPc = 7.5), indicative of efficient electron transfer processes. Furthermore, the Co-MOFs significantly augmented the kinetics of the oxygen evolution reaction (OER) in an alkaline aqueous solution, highlighting its potential as a superior catalyst in energy-related electrochemical applications. This work not only contributes to the field of MOF synthesis but also sets the stage for future explorations into their practical applications in sustainable energy systems. Keywords: Electrochemical properties, metal-organic framework, oxigen evolution reaction catalyst, 4,4’-bipyridine.
Preparation of Magnetic Activated Carbons from Cassava Peel using H3PO4 and KOH Activation by Microwave Heating for Naphthol Blue-Black Adsorption Widi Astuti, Irene Nindita Pradnya, Ria Wulansarie, Dhoni Hartanto, Triastuti Sulistyaningsih, Cepi Kurniawan, Miftakhul Hidayah, Lu'lu' Fitriana, Muhammad Arief Mahardhika, Evin Fajri Irchamsyah Trends in Sciences, 2024 To address the separation problems and produce the reusable adsorbent, cassava peel magnetic activated carbon (MAC) prepared via microwave-assisted activation has been proposed to replace activated carbon (AC) for naphthol blue-black removal. To create MACs, ACs were embedded with nano-sized magnetite particles using co-precipitation methods. In this sense, 2 different activating agents (i.e., H3PO4 and KOH) have been used. H3PO4 activation provides a larger pore size and more functional groups, while KOH activation provides a larger surface area and higher porosity. The increase of H3PO4 concentration from 40 to 60 % leads to an increase in porosity as well as an increase in the weight ratio of KOH to char from 1 to 3. Impregnation magnetite to the ACs reduces surface area from 457.76 to 337.94 m2 g-1 for KOH activation, and from 360.65 to 232.74 m2 g-1 for H3PO4 activation, decreasing adsorption capacity from 97.5 to 97 % for KOH activation and from 99 to 98 % for H3PO4 activation. However, the adsorbent is easy to separate under the magnetic influence. The adsorption data of MAC by H3PO4 activation show suitability with the Redlich-Peterson isotherm model, suggesting that naphthol blue-black removal is not ideal monolayer adsorption, but a combination of physisorption and chemisorption processes that exhibit heterogeneity of naphthol blue-black adsorption on the surface of adsorbent. Meanwhile, for MAC by KOH activation, the Langmuir isotherm is more suitable. HIGHLIGHTS Cassava peel was used in the preparation of magnetic activated carbon The effect of microwave-assisted H3PO4 and KOH activation was discussed Prediction of isotherm models was proposed and compared GRAPHICAL ABSTRACT
The Application of Entomopathogenic Fungi Metarhizium anisopliae, Beauveria bassiana, and Trichoderma harzianum for Coptotermes curvignathus and Cryptotermes cynocephalus Termite Control in Indonesia Niken SUBEKTI, Ari SUSILOWATI, Elizabeth Novi KUSUMANINGRUM, Anita FADHILA, Sania SALSABILA, Citra Anisah ZAHRA, Nasiha Al SABRINA, Ikhsan GUSWENRIVO, Yayan SANJAYA, Cepi KURNIAWAN, Apri Heri ISWANTO, Mia MIRANTI Journal of the Korean Wood Science and Technology, 2024 In Indonesia, Coptotermes curvignathus Holmgren and Cryptotermes cyanocephalus Light termite attacks can damage wood and causing losses of 8.7 trillion rupiah per year. Wood treatment and soil barrier are very important to protect structures and their components from termite infestation. The application of synthetic chemicals that pose risks to the environment and human health. The growing movement to replace these chemicals with new termiticides that are safe for the environment in place of persistent organic pollutants. Efficacy performance in entomopathogenic fungi spores such as that produce decanoic acid, hexadecanoic acid, palmitic acid, and octadecadienoic acid are potential compounds that provide for ecofriendly termite control. Entomopathogenic fungal spores from Metarhizium anisopliae , Trichoderma harzianum , and Beauveria bassiana , as the active ingredient were formulated with nanocellulose was added as an inert ingredient to which helped to deliver the active ingredients on controlling the target pest, and enhance the utility ability of the product fungi to control termites. The mortality of these termites successively entomopathogenic fungi was the main cause of death. The higher concentrations being associated with of nanocellulose used affect increased the number of termites mortality. M. anisopliae paired with 60% nanocellulose concentrate was the best percentage for yielded the greatest C. curvignathus and C. cynocephalus termite control. In the field testing, M. anisopliae provided better, it showed the finest result of termite control rather than B. bassiana and T. harzianum . The results of the research indicate that entomopathogenic fungi can be used for Pest Control Management as the subterranean termite and drywood termite control.
Synthesis of tetranuclear zinc(II) azomethine complex: A comparative appraisal between conventional and microwave-assisted methods Malaysian Journal of Chemistry, 2020
Effect of SrO content on Zeolite Structure N Widiarti, U S Sari, F W Mahatmanti, Harjito, C Kurniawan, D Prasetyoko, Suprapto Iop Conference Series Materials Science and Engineering, 2018
Corrosion retardation of mild steel electrodeposited with 4-hydroxybenzalaniline in 0.5 M NaCl International Journal of Engineering and Technology Uae, 2018
