Detection of C-Reactive Protein Using Histag-HRP Functionalized Nanoconjugate with Signal Amplified Immunoassay

Area of Science:

• Biomarker Detection
• Nanotechnology
• Immunoassays

Background:

• Conventional enzyme-linked immunosorbent assay (ELISA) lacks sensitivity and speed for early disease detection.
• Existing nanoprobes often involve complex synthesis and detection methods.
• There is a need for rapid, simple, and sensitive nanoprobe-based assays for clinical diagnostics.

Purpose of the Study:

• To develop a novel, ultrasensitive gold nanoprobe for enhanced colorimetric detection in ELISA.
• To improve the sensitivity and reduce the assay time for C-reactive protein (CRP) detection.
• To create a cost-efficient and versatile immunoassay platform for biomarker detection.

Main Methods:

• Synthesized gold nanoparticles conjugated with 6X-histidine (6X-his) peptide and nickel-horseradish peroxidase (Ni2+-HRP).
• Utilized the functionalized nanoprobe in an ELISA format for C-reactive protein (CRP) detection.
• Validated the assay performance using standard and serum samples, comparing it with conventional ELISA.

Main Results:

• Achieved an ultrasensitive detection limit of 32.0 pg/mL for CRP with high reproducibility (R2 = 0.98).
• Demonstrated a 12-fold increase in sensitivity for CRP detection compared to conventional ELISA.
• Confirmed a simple, fast, and cost-efficient assay with easy nanoprobe synthesis.

Conclusions:

• The developed 6X-his/Ni2+-HRP functionalized gold nanoprobe significantly enhances ELISA sensitivity and speed.
• This novel immunoassay offers a promising, cost-effective platform for early disease biomarker detection.
• The flexible nanoprobe design can be adapted for detecting various other biomarkers.