Judul: Glucose biosensor using a glucose dehydrogenase flavin adenine dinucleotide electrochemically immobilized on zeolite nanoparticles
Abstrak: A glucose biosensor was developed to measure blood glucose levels. The performance of these new glucose biosensors was continuously improved, producing better performance and stability. The technique selection and immobilization matrix are key factors for biosensor development, so that the prospecting of materials that can be used as a matrix for supporting enzyme, continue to be explore. The purpose of this study was to determine the activity and stability of the enzyme glucose dehydrogenase (GDH) that were immobilized on zeolite nanoparticles (NPZ) and determine the kinetic parameters and analytical performance by electrochemical methods. The resulting enzyme electrode with NPZ and enzyme electrode with zeolite A showed a high activity against the enzyme electrode glucose than without NPZ. The reaction kinetics of third electrodes of enzyme followed the Dixon equation. The 𝐼����𝑚����𝑎����𝑥����𝑎����𝑝����𝑝���� values for enzyme electrode without NPZ, with NPZ, and with zeolite A were 27.25 μA, 77.52 μA, and 48.54 μA, respectively. The 𝐾����𝑀����𝑎����𝑝����𝑝���� values for GDH enzyme that immobilized on the NPZ were 1.16 mM, 12.30 mM for GDH enzyme that immobilized on zeolite A and 0.95 mM for GDH enzyme immobilization without NPZ. The enzyme electrode without NPZ, with NPZ, and with zeolite A also showed a high sensitivity with value for the sensitivity were 0.58 μA mM-1, 0.81 μA mM-1, and 2.51 μA mM-1, respectively. The third enzyme electrodes showed different linear area with range for the enzyme electrode without NPZ, with NPZ and with zeolite A were 1.00-15.00 mM, 2.00-20.00 mM, and 0.06-10.00 mM, respectively. The blood glucose level of normal person ranged from 4 to 6 mM, so that the enzyme electrode with NPZ and without NPZ are suitable for use in the determination of the concentration of blood glucose. While the enzyme electrode with zeolite A has a smaller range so it is more suitable to use in the determination of glucose concentration in the foods or beverages. The enzyme electrode with NPZ and the enzyme electrode with zeolite A showed a good accuracy with relative error values were 3.84% and3.48%, respectively. Repeatability measurements also showed a good precission results with relative standard deviation values (%RSD) for the enzyme electrode with NPZ and enzyme electrode with zeolite A were 3.83% and 3.16%, respectively. By combining two immobilization techniques, physical adsorption on zeolite and entrapment on carbon paste, high enzymatic activity, good accuracy, and repeatability was attained. The enzyme electrode with NPZ and the enzyme electrode with zeolite A demonstrated a good electrochemical response toward glucose, allowing it to detect blood glucose levels and glucose levels in foods and beverages.
Keyword: glucose biosensor, immobilization, zeolite

Judul: Activity and stability of glucose biosensor based on Escherichia coli immobilized on zeolite-glutaraldehyde
Abstrak: Biosensor glukosa berbasis Escherichia coli hingga saat ini telah dikembangkan. Pengembangan ini memiliki beberapa kelemahan, yaitu aktivitas glukosa dehidrogenase (GDH) dan stabilitas elektrode rendah. Penggunaan zeolit pada biosensor dapat meningkatkan aktivitas enzim, sedangkan penggunaan glutaraldehida (GA) sebagai bahan taut-silang dapat meningkatkan stabilitas elektrode. Perancangan percobaan optimisasi dilakukan menggunakan metode permekaan respons (RSM). Kondisi optimum aktivitas biosensor ini ialah suhu 30 oC, pH 6, konsentrasi glukosa 15 mM, konsentrasi pirolokuinolina kuinon (PQQ) 3.5 μM, zeolit 150 mg/mL, dan konsentrasi GA 14.05%. GDH sel E. coli terimobilisasi dapat mendeteksi konsentrasi glukosa hingga 50 mM. Reaksi kinetika GDH sel E. coli terimobilisasi mengikuti persamaan Lineweaver-Burk. Nilai KM app dan Imaks app biosensor ini secara berturut-turut adalah 2.69 mM dan 3.73 μA. Aktivitas GDH sel bakteri relatif stabil sebesar 70–80% selama 4 hari. Oleh karena itu, penggunaan zeolit-GA sebagai matriks imobilisasi dapat meningkatkan aktivitas GDH sel bakteri E. coli yang relatif stabil.
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Judul: Warna bulu kucing ras persia: variasi pola warna dan pewarisannya
Abstrak: Kucing Persia mempakan kucing rasyang paling urnum dijumpai di Indonesia. Kucing Persia memiliki bulu yang panjang dengan variasi wama bulu yang sangat beragam. Perkawinan yang lebih terarah sangat perlu dilakukan untuk meningkatkan kualitas genetik warna dan pola wama bulu kucing. Penelitian ini bertujuan untuk rnempelajari variasi warna dan pola wama bulu kucing Persia yang terdapat di Indonesia, yang dilakukan di kantor pusat Cat Fancy Indonesia mulai bulan Oktober 2000 sampai Januari 2001. Data yang digunakan rnempakan data pedigree kucing Persia yang tercatat di Cat Fancy Indonesia dari tahun 1997 sampai Oktober 2001 yang terdiri dari 187 jantan dan 258 betina, selain itu juga dilakukan pengamatan langsung kepada tiga penyayang dan breeder kucing yang ada di Bandung.
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