College of Life Sciences, Northwest Normal University, Lanzhou 730070, China.
Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, Northwest Normal University, Lanzhou 730070, China.
Biosensors (Basel). 2021 May 30;11(6):174. doi: 10.3390/bios11060174.
In this paper, we propose a simple colorimetric method for the sensitive and selective detection of alkaline phosphatase (ALP) activity based on the turn off/turn on oxidase mimic activity of His@AuNCs. His@AuNCs/graphene oxide hybrids (His@AuNCs/GO) were easily obtained using the self-assembly method with poly (diallyldimethylammonium chloride) (PDDA)-coated GO and showed high oxidase-like activity compared with His@AuNCs. We found that the pyrophosphate ion (PO, PPi) could effectively inhibit the oxidase mimic activity of His@AuNCs/GO, and the hydrolysis of PPi by ALP restored the inhibited activity of His@AuNCs/GO, enabling them to efficiently catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to generate the blue oxidized product oxTMB. The intensity of the color showed a linear dependency with the ALP activity. ALP was detected in the linear range of 0-40 mU/mL with a low detection limit (LOD) of 0.26 mU/mL (S/N = 3). The proposed method is fast, easy, and can be applied to monitor the ALP activity in serum samples accurately and effectively, which suggests its practicability and reliability in the detection of ALP activity in clinical practice.
本文提出了一种基于 His@AuNCs 的关闭/开启氧化酶模拟活性来灵敏和选择性检测碱性磷酸酶（ALP）活性的简单比色法。His@AuNCs/氧化石墨烯杂化物（His@AuNCs/GO）通过带正电荷的聚二烯丙基二甲基氯化铵（PDDA）包覆的 GO 的自组装方法很容易获得，并且与 His@AuNCs 相比表现出更高的氧化酶样活性。我们发现焦磷酸根离子（PO，PPi）可以有效地抑制 His@AuNCs/GO 的氧化酶模拟活性，而 ALP 对 PPi 的水解恢复了 His@AuNCs/GO 的抑制活性，使其能够有效地催化 3,3',5,5'-四甲基联苯胺（TMB）的氧化生成蓝色氧化产物 oxTMB。颜色的强度与 ALP 活性呈线性关系。ALP 在 0-40 mU/mL 的线性范围内检测，检测限（LOD）低至 0.26 mU/mL（S/N = 3）。该方法快速、简便，可用于准确有效地监测血清样品中的 ALP 活性，表明其在临床实践中检测 ALP 活性的实用性和可靠性。
