Highly Sensitive RNA-Based Electrochemical Aptasensor for the Determination of C-Reactive Protein Using Carbon Nanofiber-Chitosan Modified Screen-Printed Electrode Articles uri icon

publication date

  • February 2022

start page

  • 415

end page

  • 430


  • 3


  • 12

International Standard Serial Number (ISSN)

  • 2079-4991


  • 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 nanofiberchitosan
    (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 (Kd) 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.


  • Electronics


  • aptasensor; electrochemical measurement; c-reactive protein; carbon nanofiber; screen; printed electrode; redox indicator