Judul: Pengembangan Biosensor dengan Menggunakan Teknik Screen Printing untuk Deteksi Kadar Kolesterol
Abstrak: Telah dilakukan pengembangan biosensor kolesterol dengan metode screen printing. Desain elektroda dengan konfigurasi tiga elektroda kemudian dikarakterisasi konduktifitas AC dan impedansi AC elektroda kerja dengan variasi frekuensi 42 Hz sampai dengan 100 kHz. Proses imobilisasi enzim kolesterol oksidase dengan mediator 1,1’-Dimethylferrocene dilakukan pada suhu ruangan dengan cara drop coating pada permukaan elektroda kerja. Setelah itu pengujian strip biosensor kolesterol dilakukan dengan teknik cyclic voltammetry. Sampel kolesterol yang digunakan 100 mg/dl, 125 mg/dl, 150 mg/dl, 175 mg/dl, 200 mg/dl, 250 mg/dl, 300 mg/dl. Pengujian stabilitas strip biosensor dilakukan dengan menyimpan strip biosensor yang telah diimobilisasi enzim ke dalam refrigerator selama delapan hari dengan suhu -150C. Hasil penelitian didapat konduktifitas AC dan impedansi AC elektroda kerja sebesar 4,8 x 10-4 Siemens.m-1 dan 9,039 KΩ. Sensitifitas biosensor kolesterol diperoleh sebesar 3x10-7 μA.mg-1dl dan sensitifitas biosensor kolesterol hari ke-8 menurun 97% dari nilai sensitifitas hari ke-0 menjadi 9x10-9μA.mg-1dl sehingga stabilitas penyimpanan strip biosensor sangat tidak stabil dan memuaskan. Akurabilitas strip biosensor kolesterol diperoleh sangat rendah.
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Judul: Biosensor Kolesterol Berbasis Amobilisasi Kolesterol Oksidase pada Pasta Karbon Termodifikasi Nanoserat Polianilin.
Abstrak: Polyaniline nanofibre was found to increase the activity of the enzyme glucose oxidase in glucose biosensors. Therefore, this study aims to examine the effects of the usage of polyaniline nanofibre as electrode on the amobilized cholesterol oxidase activity. Research methods include synthesis and characterization of polyaniline nanofibre, cyclic voltammogram measurement of carbon paste electrodes (CPE) and a modified carbon paste electrodes (MCPE), immobilization of enzymes, as well as the optimization of the electrode working conditions. The result, MCPE, as immobilization media of cholesterol oxidase with glutaraldehyde as crosslinking agent, can detect levels of cholesterol in hypocholesterolemia conditions (normal <200 mg/dL). Sensitivity of sensor is 2.34 mA/mMcm2 at pH 8 and temperature of 45oC. Affinity of substrate-enzyme is also high with Km and Imax of 2.38 mM and 6.15 mA respectively. Beside that, the surface concentration of 0.002 mol/cm2 so generated MCPEChod+Glu could be potentially as cholesterol biosensor.
Keyword: biosensors, cholesterol, cholesterol oxidase, electrodes, polyaniline

Judul: Studi Taksonomi Katak Subgenus Papurana (Lesson, 1831) dari Halmahera (Anura, Ranidae, Hylarana), Studi Taksonomi Katak Subgenus Papurana (Lesson, 1831) dari Halmahera (Anura, Ranidae, Hylarana
Abstrak: I reevaluated taxonomic of subgenus Papurana position from Halmahera based on morphological and molecular analyses. My results show that two separate species occur on the Halmahera Island, each nested within two distinct clades (hereafter papua clade and celebensis clade), one of which corresponds to H. moluccana (celebensis clade) and the other to an unidentified species (papua clade). By p-distance ranging from 6.9 to 11.5% on the 16S rRNA gene, the unidentified species (Hylarana sp.) is genetically different from all congeners of the papua clade. The Hylarana sp. can be distinguished from all congeners by following combination of charactes: vomer teeth in two oblique rows with narrow inter-vomer distance; snout rounded dorsally; dorsum with few scattered cone-shaped tubercles that are black with white tips; distinct skin folds (ridges) on the dorsal side of the thigh coinciding with dark brown cross bars; a marbled pattern on the ventral side of the thigh and yellowish groin. I also present new data for H. daemeli, H. volkerjane, and H. arfaki from the western region of Papua. Furthermore, I found that H. celebensis has numerous mtDNA lineages, indicating cryptic diversity within the celebensis clade. The discovery of two separate species on Halmahera necessitates more research into the biogeographic history of Hylarana in Northern Moluccas.
Keyword: frog, Halmahera, Hylarana, morphology, Papurana, phylogenetic