Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India.
Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India.
Enzyme Microb Technol. 2021 Feb;143:109716. doi: 10.1016/j.enzmictec.2020.109716. Epub 2020 Nov 23.
A high- power ultrasonic method was used to prepare bilirubin oxidase nanoparticles (BOxNPs) which were immobilized on polyethylene (PE) film. The characterization of PE film bound to BOxNPs and BOxNPs was carried out using "Dynamic Light Scattering (DLS)," "Transmission Electron Microscopy (TEM)," and "Scanning Electron Microscopy (SEM)." The PE film was treated with nitric acid (HNO) for its activation. BOxNPs bound to PE film exhibited optimal activity (pH-8), incubation time (11 s) with temperature 35 °C. A linear relationship was observed between the bilirubin concentrations (0.02-250 μM), with an apparent Km value and Vmax for PE- bound BOxNPs, at 0.015 μM and 2.56 μmol/mL/min. The mean recoveries of added serum bilirubin were 94.5 % at a level of 5 mM whereas 98.5 % were observed at 10 mM which showed the satisfactory reliability of BOxNPs immobilized on PE film. The coefficient of variation for serum bilirubin ranged between 4.52%-5.25%, measured on the first day (within batch) and after seven days of storage (between batch).This current method has showed a good correlation for bilirubin values when compared to the standard enzymatic colorimetric method using free enzyme. BOxNPs bound to PE film were reutilized 150 times with storage at 4 °C for 120 days.
采用高强超声法制备胆红素氧化酶纳米颗粒（BOxNPs），并将其固定在聚乙烯（PE）膜上。采用“动态光散射（DLS）”、“透射电子显微镜（TEM）”和“扫描电子显微镜（SEM）”对与 BOxNPs 结合的 PE 膜和 BOxNPs 进行了表征。PE 膜经硝酸（HNO）处理后进行活化。固定在 PE 膜上的 BOxNPs 表现出最佳活性（pH-8），孵育时间（11 秒），温度为 35°C。在胆红素浓度（0.02-250 μM）范围内观察到线性关系，PE 结合的 BOxNPs 的表观 Km 值和 Vmax 值分别为 0.015 μM 和 2.56 μmol/mL/min。在 5 mM 水平时，添加的血清胆红素的平均回收率为 94.5%，在 10 mM 时回收率为 98.5%，表明固定在 PE 膜上的 BOxNPs 具有良好的可靠性。在第一天（批内）和储存 7 天后（批间），血清胆红素的变异系数在 4.52%-5.25%之间。与使用游离酶的标准酶比色法相比，该方法显示出良好的胆红素值相关性。固定在 PE 膜上的 BOxNPs 在 4°C 下储存 120 天后可重复使用 150 次。
