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

Abstract

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 (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.

Rapid Optical Biosensing of SARS-CoV-2 Spike Proteins in Artificial Samples

“…The recognition element of an optical biosensor can be classified into aptamer, molecularly imprinted polymer (MIP), and antibody. Tabrizi et al detected RBD with the use of an MIP as capture, allowing the detection of RBD in the concentration range between 2 and 40 pg/mL with a limit of detection (LoD) of 0.7 pg/mL [ 10 ]. Cennamo et al detected RBD at the concentration of 37 nM by using aptamer as the recognition element [ 11 ].…”

Electrochemical Sensing Based on Nanofibers Modified Electrodes for Application in Diagnostic, Food and Waste Water Samples

“…A list of reported NF-based sensors and biosensors for various biomarkers are presented in Table S5. [43][44][45][46] As indicated, most biosensors have used antibodies as biological recognition elements for highly selective and sensitive biomarker detection. However, the stability and reproducibility of the developed biosensors (immunosensors) based on antibodies are still problematic.…”

“…In a recent study, Amouzadeh Tabrizi and Acedo [45] reported a highly sensitive electrochemical aptasensor for the detection of c‐reactive protein (CRP) as a biomarker associated with 2019 coronavirus disease (COVID‐19). They designed a portable aptasensor based on the modification of SPE with a composite of CNF and chit.…”

“…They compared their results with those from ELISA kit as a routine method and didn't find significant differences. A list of reported NF‐based sensors and biosensors for various biomarkers are presented in Table S5 [43–46] . As indicated, most biosensors have used antibodies as biological recognition elements for highly selective and sensitive biomarker detection.…”

An electrochemical membrane-based aptasensor for detection of severe acute respiratory syndrome coronavirus-2 receptor-binding domain

“…Nowadays, nanomaterials have been used to increase the analytical performance of electrochemical sensors [33] , [34] . Among them, the nanoporous anodic aluminium oxide (NPAOM) has drawn tremendous interest in developing electrochemical biosensors due to its three-dimensional (3D) structure, high surface area, low-cost, easy fabrication, biocompatibility, and high mechanical stability [35] , [36] , [37] .…”