College of Life and Science, Sichuan Agricultural University, Ya'an 625014, China.
Biosens Bioelectron. 2011 Apr 15;26(8):3614-9. doi: 10.1016/j.bios.2011.02.014. Epub 2011 Feb 16.
In this paper, we demonstrated that bovine serum albumin (BSA) stabilized Au clusters exhibited highly intrinsic peroxidase-like activity. Unlike nature enzymes, the BSA-Au clusters have strong robustness and can be used over a wide range of pH and temperature. Because of ultra-small size, good stability and high biocompatibility in water solution compare with other kinds of nanoparticles as peroxidase mimetics, such as Fe(3)O(4), FeS or graphene oxide, it is more competent for bioanalysis. Furthermore, we make use of the novel properties of BSA-Au clusters as peroxidase mimetics to detect H(2)O(2). The as-prepared BSA-Au clusters were used to catalyze the oxidation of a peroxidase substrate 3,3,5,5-tetramethylbenzidine (TMB) by H(2)O(2) to the oxidized colored product, and which provides a colorimetric detection of H(2)O(2). As low as 2.0 × 10(-8)M H(2)O(2) could be detected with a linear range from 5.0 × 10(-7) to 2.0 × 10(-5)M via this method. More importantly, a sensitive and selective method for xanthine detection was developed using xanthine oxidase (XOD) and the as-prepared BSA-Au clusters. The detection limit of this assay for xanthine was 5 × 10(-7)M and the proposed method was successfully applied for the determination of xanthine in urine and human serum sample.
在本文中，我们证明牛血清白蛋白（BSA）稳定的 Au 团簇表现出高度内在的过氧化物酶样活性。与天然酶不同，BSA-Au 团簇具有很强的稳健性，可以在很宽的 pH 和温度范围内使用。由于与其他种类的纳米粒子（如 Fe(3)O(4)、FeS 或氧化石墨烯）相比，BSA-Au 团簇具有超小尺寸、良好的稳定性和在水溶液中的高生物相容性，作为过氧化物酶模拟物，它更适合生物分析。此外，我们利用 BSA-Au 团簇作为过氧化物酶模拟物的新颖性质来检测 H(2)O(2)。所制备的 BSA-Au 团簇被用于催化 H(2)O(2)对过氧化物酶底物 3,3,5,5-四甲基联苯胺（TMB）的氧化，生成氧化的有色产物，从而提供对 H(2)O(2)的比色检测。通过这种方法，可以检测低至 2.0×10(-8)M 的 H(2)O(2)，线性范围从 5.0×10(-7)到 2.0×10(-5)M。更重要的是，利用黄嘌呤氧化酶（XOD）和所制备的 BSA-Au 团簇开发了一种灵敏和选择性的黄嘌呤检测方法。该测定法对黄嘌呤的检测限为 5×10(-7)M，该方法成功应用于尿液和人血清样品中黄嘌呤的测定。
