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CO2 electrochemical reduction (CO2ER) activity is known to be influenced by electrode materials. In this study, we report the fabrication of a copper-nickel-modified boron-doped diamond (CuNi-BDD) electrode using wet chemical seeding and electrodeposition. Annealing was performed to improve the stability of the modified electrode during elec-trolysis. Characterization of the modified BDD electrodes shows successful deposition without damage to the surface of the BDD support material. CO2ER was conducted with the CuNi-BDD electrode, which produces various important products including methanol, formic acid, CO, and CH4. Additionally, a different applied potential affected the product distribution. CO2ER was also conducted on the surfaces of Cu-BDD and Ni-BDD electrodes for comparison.

Neuraminidase sensors have been developed using platinum (Pt) and platinum-modified boron-doped diamond (PtBDD) electrodes based on the difference of electrochemical responses of zanamivir in the absence and in presence of neuraminidase. Cyclic voltammetry of zanamivir showed that the presence of zanamivir decreases the oxidation reduction peak currents of Pt. The responses were found to be linear in the zanamivir concentration range of 7.5-150 µM. Comparison between Pt-BDD and Pt bulk electrodes showed that Pt-BDD offers approximately two times higher sensitivity of zanamivir responses than Pt bulk. Further comparison to gold-based electrodes showed that Pt-based electrodes provided about one order higher sensitivity of zanamivir responses. In the presence of neuraminidase, the oxidation-reduction currents of Pt again increase. Observation on the oxidation currents in the system with 2 x 10-5 M zanamivir showed that the responses were linear in the neuraminidase concentration range of 5-20 mU. Good reproducibility with an RSD < 3 (n = 10) was achieved even when the measurements were performed in a mucin matrix, suggesting that Pt-based electrodes are suitable to be applied for the detection method of neuraminidase

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.

CO2 electrochemical reduction (CO2ER) activity is known to be influenced by electrode materials. In this study, we report the fabrication of a copper-nickel-modified boron-doped diamond (CuNi-BDD) electrode using wet chemical seeding and electrodeposition. Annealing was performed to improve the stability of the modified electrode during electrolysis. Characterization of the modified BDD electrodes shows successful deposition without damage to the surface of the BDD support material. CO2ER was conducted with the CuNi-BDD electrode, which produces various important products including methanol, formic acid, CO, and CH4. Additionally, a different applied potential affected the product distribution. CO2ER was also conducted on the surfaces of Cu-BDD and Ni-BDD electrodes for comparison. [ABSTRACT FROM AUTHOR]

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An immunochromatographic strip test based on the complex reaction of antigen-antibody (melamine-antimelamine) was developed for quantitative detection of melamine. Gold nanoparticles (AuNP) were used to form AuNP-labeled antibody, which then acted as a biosensor. Melamine quantification was performed by the determination of AuNP using anodic stripping voltammetry technique with a boron-doped diamond as the working electrode. With sample volume of 100μL and immunoreaction time of 7 min, the developed immunochromatographic strip test produced a linear calibration curve for melamine concentration range of 0-0.6 mg/L, with detection limit of 0.1 mg/L and RSD of ~5%. Furthermore, negative results were obtained for samples containing cyanuric acid and urea, indicating that the developed immunochromatographic strip test has potential for selective and quantitative detection of melamine. Strip test berbasis imunokromatografi berdasarkan reaksi pembentukan kompleks antigen-antibodi (melamin-antimelamin) dikembangkan untuk mendeteksi melamin secara kuantitatif. Nanopartikel emas (AuNP) digunakan sebagai label pada antibodi untuk membentuk antibodi berlabel AuNP yang kemudian berfungsi sebagai biosensor. Kuantifikasi melamin diperoleh dengan menentukan konsentrasi AuNP menggunakan teknik anodic stripping voltammetry. Boron-doped diamond digunakan sebagai elektroda kerja. Dengan volume sampel 100μL dan waktu imunoreaksi 7 menit, strip test menghasilkan kurva linier pada kisaran konsentrasi 0-0,6 mg/L dengan batas deteksi 0.1 mg/L dan RSD ~5%. Selain itu hasil negatif diperoleh ketika strip test diaplikasikan pada sampel yang mengandung asam sianurat dan urea, hal tersebut mengindikasikan bahwa strip test yang dikembangkan dapat digunakan sebagai pendeteksi melamin secara selektif dan kuantitatif. [ABSTRACT FROM AUTHOR]