Judul: Bioanoda Berbasis Lakase Trichoderma viride IPBCC 07.551 Teramobil Nanokitosan pada Elektroda Pasta Karbon Termodifikasi (EPKT) Nanoserat Polianilin
Abstrak: Lakase (p-diphenol: oksigen oksidoreduktase, EC 1.10.3.2) adalah enzim oksidoreduktase yang terdapat di beberapa tanaman tingkat tinggi, serangga, bakteri, dan fungi. Berbagai jenis lakase dilaporkan dapat digunakan sebagai biosensor. Namun, lakase dari Trichoderma viride IPBCC 05.771 belum ada informasi ilmiah mengenai kondisi pH dan suhu optimum kinerja lakase dalam bentuk bioanoda. Penelitian ini bertujuan menentukan kondisi optimum berupa pH dan suhu kinerja bioanoda berbasis lakase Trichoderma viride IPBCC 07.551. Parameter uji berupa pH optimum dan suhu optimum kinerja EPKT/Lac+Chi. Kinerja elektroda diukur dengan menggunakan metode potensiometri. Nilai puncak arus oksidasi dari EPKT/Lac-Chi dan EPKT/Lac+Chi berturut-turut adalah 15.63 mA dan 18.33 mA. Kondisi pH optimum kinerja EPKT/Lac+Chi adalah 6.0 dengan arus 91.35 mA. Kondisi suhu optimum kinerja EPKT/Lac+Chi pada suhu 45oC dengan arus 36.58 mA. Hasil menunjukkan elektroda karbon termodifikasi polianilin dengan teramobil lakase terbukti dapat meningkatkan konduktivitas arus dan sensitivitas sensor.
Keyword: bioanoda, lakase, nanokitosan, polianilin, Trichoderma viride

Judul: Biosensor based on immobilized glucose oxidase on chitosan nanoparticles in modified carbon pasta electrode by polyaniline nanofibers as biosensor applications.
Abstrak: Biosensor berbasis glukosa oksidase dikembangkan untuk mendeteksi glukosa secara lebih tepat, cepat, dan sensitif. Pengembangan biosensor yang dilakukan memanfaatkan enzim glukosa oksidase teramobil pada nanopartikel kitosan dalam elektroda pasta karbon termodifikasi. Penelitian bertujuan menentukan kondisi optimum untuk menghasilkan nanopartikel kitosan dan mengetahui karakteristik glukosa oksidase/elektroda pasta karbon termodifikasi. Hasil uji menunjukan kondisi optimum untuk membuat nanopartikel kitosan, yaitu pada volume 300 mL dan waktu sonikasi 10 menit. Penambahan polianilin pada glukosa oksidase/elektroda pasta karbon termodifikasi dapat meningkatkan arus. Glukosa oksidase/elektroda pasta karbon termodifikasi memiliki kondisi optimum pada pH 5.0 dan konsentrasi glukosa sebesar 20 mM. Daerah linier berada pada 0.6-1.8 mM dan nilai sensitivitas elektroda sebesar 0.20 mA/mM. Nilai Km dan Imaks pada sebesar 1.934 mM dan0.937 mA ditentukan dengan metode Lineweaver-Burk. Hasil penelitian ini akan digunakan selanjutnya untuk pengembangan biosensor glukosa., Biosensor based on glucose oxidase enzyme has been developed to detect glucose levels more precise, rapid, and sensivity. The development of biosensor was used glucose oxidase immobilized on chitosan nanoparticles in modified carbon paste electrode. The purpose of this study were to determine the optimum condition in order to produce chitosan nanoparticles and to obtain characteristic of glucose oxidase/modified carbon pasta electrode. The result showed that optimum conditions were obtained to make chitosan nanoparticles with 300 mL of volume and 10 minutes of ultrasonication time. The addition of polyaniline on glucose oxidase/modified carbon pasta electrode increased the current. Glucose oxidase/modified carbon pasta electrode had optimum conditions at pH 5.0 and glucose concentration was 20 mM. Linier range was 0.6-1.8 mM dan sensitivity value of electrode was 0.20 mA/mM. Km and Imax value were 1.934 mM was 0.937 mA determined by Lineweaver-Burk method. These result will be further used for development of glucose biosensor. Key words: glucose biosensor, glucose oxidase, chitosan nanoparticles, polyaniline.
Keyword: biosensor glukosa, glukosa oksidase, nanopartikel kitosan, polianilin

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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