Amouzadeh Tabrizi Mahmoud, Acedo Pablo
Electronic Technology Department, Universidad Carlos III de Madrid, 28911 Leganés, Spain.
Nanomaterials (Basel). 2022 Jan 27;12(3):415. doi: 10.3390/nano12030415.
C-reactive protein (CRP) is one of the biomarkers related to coronavirus disease 2019 (COVID-19). Therefore, it is crucial to develop a highly sensitive, selective, and cost-effective biosensor for the determination of CRP. In this study, we designed an electrochemical aptasensor. For this purpose, the surface of a carbon screen-printed electrode was first modified with a carbon nanofiber-chitosan (CNFs-CHIT) nanocomposite. After that, the amino-terminal RNA aptamer probes were linked to the amino groups of CHIT via glutaraldehyde as the cross-linker. Finally, methylene blue (MB) as a redox probe was self-assembled on the surface of the aptasensor. The obtained results indicated that the CNFs-CHIT nanocomposite increased the surface coverage of the aptamer up to 5.9 times. The square-wave voltammetry was used for the measurement of CRP concentration in the linear range of 1.0-150.0 pM. The obtained results indicated that the signal had a logarithmic relationship with the concentration of CRP. The limit of detection (LOD) was obtained to be 0.37 pM. The dissociation constant (K) that demonstrates the affinity of the aptamer probe to its target was found to be 0.93 pM. The analytical performances of the proposed RNA aptasensor were better than the previously reported aptasensors for CRP. The proposed aptasensor was also applied for the determination of CRP in the human plasma samples. The obtained results indicated that there were no statistically significant differences between the responses of the proposed RNA aptasensor and an enzyme-linked immunosorbent assay kit (ELISA). The analytical performances of the proposed RNA aptasensor described in this paper are better than previously reported aptasensors for CRP determination.
C反应蛋白（CRP）是与2019冠状病毒病（COVID-19）相关的生物标志物之一。因此，开发一种用于测定CRP的高灵敏度、高选择性且经济高效的生物传感器至关重要。在本研究中，我们设计了一种电化学适体传感器。为此，首先用碳纳米纤维-壳聚糖（CNFs-CHIT）纳米复合材料修饰碳丝网印刷电极的表面。之后，通过戊二醛作为交联剂将氨基末端RNA适体探针连接到壳聚糖的氨基上。最后，将亚甲基蓝（MB）作为氧化还原探针自组装在适体传感器的表面。所得结果表明，CNFs-CHIT纳米复合材料使适体的表面覆盖率提高了5.9倍。采用方波伏安法在1.0 - 150.0 pM的线性范围内测量CRP浓度。所得结果表明，信号与CRP浓度呈对数关系。检测限（LOD）为0.37 pM。发现证明适体探针对其靶标的亲和力的解离常数（K）为0.93 pM。所提出的RNA适体传感器的分析性能优于先前报道的用于CRP的适体传感器。所提出的适体传感器还用于测定人血浆样品中的CRP。所得结果表明，所提出的RNA适体传感器与酶联免疫吸附测定试剂盒（ELISA）的响应之间没有统计学上的显著差异。本文所述的所提出的RNA适体传感器的分析性能优于先前报道的用于CRP测定的适体传感器。
