State Key Laboratory of Precision Blasting, Jianghan University, Wuhan 430056, PR China; Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education, College of Photoelectric Materials and Technology, Jianghan University, Wuhan 430056, Hubei, China.
Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education, College of Photoelectric Materials and Technology, Jianghan University, Wuhan 430056, Hubei, China.
Talanta. 2023 Oct 1;263:124700. doi: 10.1016/j.talanta.2023.124700. Epub 2023 May 26.
Immunosorbent assay is one of the most popular immunological screening techniques which has been widely used for the clinical diagnosis of alpha-fetoprotein (AFP). While traditional immunosorbent assay (ELISA) suffers from low detection sensitivity due to its low intensity of colorimetric signal. To improve the sensitivity of AFP detection, we developed a new and sensitive immunocolorimetric biosensor by combining Ps-Pt nanozyme with terminal deoxynucleotidyl transferase (TdT)-mediated polymerization reaction. The determination of AFP was achieved by measuring the visual color intensity produced by the catalytic oxidation reaction of the 3,3',5,5'-tetramethylbenzidine (TMB) solution with Ps-Pt and horseradish peroxidase (HRP). Owing to the synergistic catalysis of Ps-Pt and horseradish peroxidase HRP enriched in polymerized amplification products, this biosensor exhibited a significant color change within 25 s in the presence of 10-500 pg/mL AFP. This proposed method allowed for the specific detection of AFP with a detection limit of 4.30 pg/mL and even 10 pg/mL target protein could be distinguished clearly by visual observation. Furthermore, this biosensor could be applied to analysis of AFP in the complex sample and could be easily extended to the detection of other proteins.
免疫吸附测定法是最受欢迎的免疫学筛选技术之一，已广泛用于甲胎蛋白（AFP）的临床诊断。然而，传统的免疫吸附测定法（ELISA）由于比色信号强度低，检测灵敏度较低。为了提高 AFP 检测的灵敏度，我们通过将 Ps-Pt 纳米酶与末端脱氧核苷酸转移酶（TdT）介导的聚合反应相结合，开发了一种新的、灵敏的免疫比色生物传感器。通过测量 Ps-Pt 和辣根过氧化物酶（HRP）催化氧化 3,3',5,5'-四甲基联苯胺（TMB）溶液产生的视觉颜色强度来实现 AFP 的测定。由于 Ps-Pt 和在聚合扩增产物中富集的辣根过氧化物酶 HRP 的协同催化作用，该生物传感器在存在 10-500 pg/mL AFP 的情况下在 25 s 内表现出明显的颜色变化。该方法允许对 AFP 进行特异性检测，检测限为 4.30 pg/mL，甚至可以通过肉眼观察清楚地区分 10 pg/mL 的目标蛋白。此外，该生物传感器可用于复杂样品中 AFP 的分析，并且可以很容易地扩展到其他蛋白质的检测。
