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Abstrak :
Modifikasi elektroda karbon, glassy carbon (GC) dan boron-doped diamond (BDD), menggunakan nanopartikel emas (AuNP) dilakukan dengan menggunakan teknik self-assembly. Teknik ini dipilih berdasarkan interaksi elektrostatik antara AuNP yang terperangkap ion sitrat dengan gugus amina yang dimodifikasikan pada BDD dan GC. Material yang diperoleh, AuNP-GC dan AuNP-BDD, kemudian digunakan sebagai elektroda pendeteksi As 3+ menggunakan teknik anodic stripping voltammetry (ASV). Anodic stripping voltammograms dari kedua elektroda menunjukkan puncak potensial oksidasi As °pada ~0.21 V (vs. Ag/AgCl) pada kondisi optimum potensial deposisi -500 mV, waktu deposisi 180 s, dan scan rate 100 mV/s. AuNP-BDD memiliki daerah pengukuran yang lebih luas (0-20 mM) dan limit deteksi yang lebih rendah (0.39 μ M atau 4.64 ppb), sedangkan AuNP-GC linier pada daerah konsentrasi 0-10 mM dengan limit deteksi 0.14 μ M (13.12 ppb). Keberulangan yang baik ditunjukkan dengan RSDs (n=20) 2.93% pada AuNP-BDD dan 4.54% pada AUNP-BDD. Meskipun demikian penurunan yang lebih banyak pada pengukuran 6 hari berturut-turut ditemukan pada AuNP-BDD (~20.1%) daripada pada AuNP-GC (~2.8%).

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Modification of carbon, including boron-doped diamond (BDD) and glassy carbon (GC), using gold nanoparticle (AuNP) was developed by self-assembly technique. This technique is based on electrostatic interaction between citrate-capped AuNP to amine terminal groups after surface modification of BDD and GC. The fabricated materials, AuNP-BDD and AuNP-GC, were then utilized as electrodes for As 3+ detection using anodic stripping voltammetry (ASV) technique. Anodic stripping voltammograms of both Au NP-BDD and AuNP-GC electrodes showed similar peak potentials of As ° oxidation at ~0.21 V (vs. Ag/AgCl) in optimum conditions of -500 mV, 180 s, and 100 mV/s for deposition potential, deposition time, and scan rate, respectively. AuNP-BDD shows better performances in the case of wide linear concentration range (0-20 mM) and low limit of detection (0.39μM or 4.64 ppb), whereas those of AuNP-GC were linear in the concentration range of 0-10mM with a detection limit of 0.14μ M (13.12 ppb). Excellent reproducibility was shown with RSDs (n=20) of 2.93% and 4.54% at AuNP-BDD and AuNP-GC, respectively. However, decreasing of current responses in 6-concecutive days was found more at AuNP-BDD (~20.1%) than that at AuNP-GC (~2.8%).

Abstrak :
Polyclonal antibodies of aflatoxin B1 were successfully produced from New Zealand White female rabbits after immunization by the hapten of aflatoxin B1-carboxymethyl hydroxylamine hemihydrochloride (AFB1-CMO) conjugated with bovine serum albumin (BSA) as the antigen. The hapten was synthesized using the carbodiimide method with CMO as a linker. Absorption peaks at 362, 264, and 218 nm were observed as a result of characterization with UV-Vis spectroscopy, while IR spectroscopy showed peaks at 3448 cm-1 and 1642 cm-1 attributable to the hydroxyl and nitrile groups, respectively. Furthermore, mass spectrometry showed fragmentation at the m/z of 386, 368.2, and 310, which confirms that the hapten of AFB1-CMO was successfully synthesized. The hapten was then conjugated with BSA to serve as an antigen of AFB1 when it was injected into the rabbits. The specificity of the antigen towards its antibody and the confirmation of hapten-BSA conjugation were characterized using the dot blot immunoassay, which showed a BSA concentration of 1.74 mg/mL. Two weeks after the primary immunization by its antigen, agar gel precipitation testing showed that the rabbit blood serum had positive results for polyclonal antibodiest against AFB1 with the highest concentration of antibodiest of 2.19 mg/mL.

Sintesa of Poliklonal Antibodi Aflatoxin B1. Antibodi poliklonal aflatoksin B1 telah berhasil diproduksi pada hewan uji kelinci betina New Zealand White setelah diimunisasi dengan hapten aflatoksin B1-carboxymethyl hydroxylamine hemihydrochloride (AFB1-CMO) yang dikonjugasikan dengan bovin serum albumin (BSA) sebagai antigen. Hapten AFB1 disintesis menggunakan metode karbodiimida dengan CMO sebagai linker. Puncak absorbansi pada 362, 264, 218 nm teramati sebagai hasil karakterisasi menggunakan spektrofotometer UV-Visibel, sementara dengan spektrum IR diperoleh puncak pada 3448.126 cm-1 dan 1642.451 cm-1 yang masing-masing mengindikasikan adanya gugus hidroksil dan nitril. Hasil spektrometri massa menunjukkan fragmentasi pada m/z 386, 368.2, dan 310 yang membuktikan hapten AFB1-CMO telah berhasil disintesis. Hapten ini kemudian dikonjugasikan dengan BSA agar dapat berperan sebagai antigen AFB1 ketika diinjeksikan pada kelinci. Kekhususan antigen aflatoksin B1 terhadap antibodinya dan konfirmasi konjugat hapten-BSA menunjukkan hasil positif pada uji dot blot immunoassay dengan konsentrasi BSA sebesar 1.74 mg/mL. Dua pekan setelah imunisasi primer, agar gel precipitation test menunjukkan hasil positif terhadap antibodi poliklonal AFB1 dengan konsentrasi tertinggi sebesar 2.19 mg/mL.