Robust and multiplexed colorimetric immunoassay for cardiovascular disease biomarkers detection in serum with high specificity

Multiplexed detection of increased CRP and IL-6 levels in serum could warn the risk of Cardiovascular Disease (CVD) in clinical diagnosis. Herein, we report a robust, simple, reliable and multiple-targeted colorimetric immunoassay platform for the detection of CVD protein biomarkers in serum with high specificity. With dual signal amplification involving in AuNPs probes via ssDNA hybridization and AuNPs initiated gold deposition, this colorimetric immunoassay achieves a limit of detection (LOD) of 326 pg/mL for CRP and a LOD of 8 pg/mL for IL-6 simultaneously. In addition, this assay exhibited high specificity and selectivity when challenged with different interfering proteins. Clinical feasibility is evaluated by utilizing this assay in clinical serum samples of CVD patients and the experimental results show a good consistency with ELSIA kit. Importantly, this immunoassay shows several advantages such as simple operation, less time-consuming, multiplex, reliability and no requirement of labelled reagents and expensive equipment, which demonstrates its potential utility in clinical diagnostics for CVD.