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"[ABSTRAKKonversi bentuk nanopartikel perak (AgNP) melalui pemanasan dan fotoinduksi terjadi dengan kehadiran sitrat sebagai capping agent dan polivinilpirolidone (PVP) sebagai stabilisator. Awalnya, assintesis nanoprisma perak (AgNP-Biru) dipanaskan selama 30 menit hingga terbentuk nanodisk perak (AgNP-Kuning). Selanjutnya, di bawah penyinaran lampu natrium nanoprisma perak(AgNP-Iradiasi) kembali terbentuk dengan ukuran yang lebih besar. Spektrofotometer UV-Vis dan transmission electron microscopy (TEM) digunakan untuk investigasi pertumbuhan dan konversi bentuk AgNP. Hasil penelitian menunjukkan bahwa parameter kisi AgNP-orange (4.0716 Å) lebih kecil dari AgNP-Iradiasi (4.3134 Å). Hal tersebut mengindikasikan terjadinya rearrangement atom perak pada permukaan AgNP. AgNP dengan bentuk bulat dan triangular diuji akivitas katalitiknya sebagai katalis homogen dan heterogen untuk reduksi 4-nitrofenol. Sebagai katalis heterogen, AgNP diimobilisasi dalam karbon aktif dan dikarakterisasi menggunakan SEM-EDX. Aktivitas katalitik AgNP-Iradiasi lebih aktif daripada AgNP-Orange. Konstanta kinetika reaksi pseudo orde satu reduksi 4-NP dengan NaBH4 adalah 0.2178 s-1 (katalis homogen) dan 0.2225 s-1 (katalis heterogen).

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ABSTRACTHeated and Photoinduced shape conversion of silver nanoparticles (AgNPs) were occurred in the presence of citrate as capping agent and polyvinylpyrrolidone (PVP) as additional stabilizer. First, the as-synthesized silver nanoprism (AgNP-Blue) were heated to transformed into silver nanodisks (AgNP-Orange) with time. Subsequently, under light irradiation (sodium lamp), an increasing fraction of silver nanoprism (AgNP-Irradiation) develop. The UV-Vis spectrophotometer and transmission electron microscopy (TEM) were adopted to investigate the growth and shape conversion of AgNPs. The result show that the lattice constant of AgNP-Orange converted by heating (4.0716 Å) less than AgNP-Irradiarion (4.3134 Å), which was possibly achieved through rearrangement of silver atoms on the surface of AgNPs. Both silver nanodisk and nanoprism were tested as homogenous and heterogeneous catalyst for reduction of 4-nitrophenol (4-NP). AgNPs supported on activated carbon were synthesized as heterogen catalyst and characterized by SEM-EDX. For catalytic application, AgNP-Irradiation were more actived than AgNP-orange. The kinetic constants of pseudo first orde reaction of reduction 4-NP with NaBH4 are 0.2178 s-1 for homogeneous and 0.2225 s-1 for heterogeneous catalyst, Heated and Photoinduced shape conversion of silver nanoparticles (AgNPs) were occurred in the presence of citrate as capping agent and polyvinylpyrrolidone (PVP) as additional stabilizer. First, the as-synthesized silver nanoprism (AgNP-Blue) were heated to transformed into silver nanodisks (AgNP-Orange) with time. Subsequently, under light irradiation (sodium lamp), an increasing fraction of silver nanoprism (AgNP-Irradiation) develop. The UV-Vis spectrophotometer and transmission electron microscopy (TEM) were adopted to investigate the growth and shape conversion of AgNPs. The result show that the lattice constant of AgNP-Orange converted by heating (4.0716 Å) less than AgNP-Irradiarion (4.3134 Å), which was possibly achieved through rearrangement of silver atoms on the surface of AgNPs. Both silver nanodisk and nanoprism were tested as homogenous and heterogeneous catalyst for reduction of 4-nitrophenol (4-NP). AgNPs supported on activated carbon were synthesized as heterogen catalyst and characterized by SEM-EDX. For catalytic application, AgNP-Irradiation were more actived than AgNP-orange. The kinetic constants of pseudo first orde reaction of reduction 4-NP with NaBH4 are 0.2178 s-1 for homogeneous and 0.2225 s-1 for heterogeneous catalyst]"

"Metode fitosintesis berhasil digunakan untuk pembuatan nanopartikel MoS2, NiO dan nanokomposit NiO/MoS2. Penggunaan alisin murni sebagai sumber sulfida berhasil digunakan pada sintesis MoS2. Sedangkan, penggunaan alisin yang berasal dari bawang putih membentuk MoS­2 dalam campuran dengan oksida lainnya. Di sisi lain, fitosintesis nanopartikel NiO menggunakan ekstrak daun bandotan juga berhasil dilakukan. Selanjutnya, nanokomposit NiO/MoS2 disintesis secara sonokimia menggunakan NiO-MA 800 dan MoS2 dari alisin murni. Nanokomposit yang terbentuk berukuran 60-80 nm. Nanokomposit NiO/MoS2 yang telah berhasil didispersikan pada permukaan Screen Printed Carbon Electrode (SPCE) memiliki respon arus yang paling tinggi pada elektropolimerisasi MO dibandingkan NiO dan MoS2. PMO/NiO/MoS2/SPCE diaplikasikan untuk sensor kolesterol dan menghasilkan linearitas yang baik (r2=0,9998) pada rentang konsentrasi 1-15 mg/dL, LOD 0,24 mg/dL, LOQ 0,81 mg/dL, sensitivitas 7,95x10-6 A mg-1 dL-1 cm-2, dan recovery 96,45 – 101,87%. Selain itu, uji interferensi pengukuran kolesterol terhadap 1mg/dL NaCl, CaCl2, tirosin dan glisin menunjukkan tidak adanya gangguan yang signifikan (perubahan respon arus <5%), sedangkan terhadap glukosa dan asam askorbat menunjukkan gangguan masing-masing sebesar 10,11-11,43% dan 6,93-13,36%. Pengukuran pada sampel nyata, yaitu pada susu dan yogurt menunjukkan kesesuaian dengan informasi nilai gizi yang tertera pada kemasan sebesar 95,7% dan 94,3% serta metode kromatografi gas sebesar 97,1% dan 95,2 %.

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The phyto-synthesis method was successfully used for the forming of MoS2, NiO, and NiO/MoS2 nanoparticles. The use of pure allicin as a sulfide source was successfully used in the synthesis of MoS2, while the use of allicin derived from garlic forms MoS2 in a mixture with the oxides. On the other hand, the phytosynthesis of NiO nanoparticles using bandotan leaf extract was also successful. Furthermore, NiO/MoS2 nanocomposites were synthesized sonochemically using NiO-MA 800 and MoS2 from pure allicin. The nanocomposites formed were 60-80 nm in size. NiO/MoS2 nanocomposites that have been successfully dispersed on the Screen Printed Carbon Electrode (SPCE) surface have the highest current response to MO electropolymerization compared to NiO and MoS2. PMO/NiO/ MoS2/SPCE was applied to cholesterol sensors and produced good linearity (r2 = 0.9998) in the concentration range of 1-15 mg/dL, LOD of 0.24 mg/dL, LOQ of 0.81 mg/dL, sensitivity of 7.95x10-6 A mg-1 dL-1 cm-2 and recovery 96.45 - 101.87%. In addition, the interference test of cholesterol measurements for 1mg/dL of NaCl, CaCl2, tyrosine, and glycine showed no significant disturbances (changes in current response <5%), while glucose and ascorbic acid showed a disturbance of 10.11-11.43% dan 6.93-13.36%, respectively. Measurements on real samples, namely milk and yogurt, show similarity with the nutritional value information listed on the packaging of 95.7% and 94.3% and gas chromatography methods of 97.1% and 95.2%."