Aptamer-Driven Biosensor Technology for the Quantitative Analysis of C-Reactive Protein

Abstract

C-reactive protein (CRP) is a widely recognized biomarker for early myocardial infarction (MI) detection, released into the bloodstream during heart inflammation. Traditional assays for CRP detection, like ELISA and immunoradiometric assays, are costly, time-consuming, and require large sample volumes. Aptasensors are becoming increasingly popular for MI diagnosis due to their affordability, simplicity, and potential for point-of-care use. In this study, an electrochemical aptasensor incorporating mercaptosuccinic acid-capped nickel selenide quantum dots (MSA-NiSe₂ QD) were developed for CRP detection. The amine-modified aptamer was immobilized on the MSA-NiSe₂ QD using EDC/NHS coupling chemistry. Chronocoulometric measurements showed high selectivity towards CRP in phosphate buffer, with a linear range of 10–110 pg/mL and a detection limit of 2.80 pg/mL. Cross-reactivity experiments confirmed the aptasensor's high selectivity for CRP. Testing in human serum samples demonstrated recovery rates of 94–100.5 %, indicating its suitability for clinical diagnostics. Validation studies with a commercial CRP ELISA kit showed the aptasensor's superior sensitivity in both physiological buffer and human serum.