High-sensitivity SpectroChip-integrated LFIA platform for rapid point-of-care quantification of cardiovascular...

Timely and precise measurement of cardiovascular biomarkers is crucial for early diagnosis and effective management of heart disease. This study evaluates THE ONE InstantCare device, a point-of-care (POC) platform that integrates a SpectroChip technology with gold nanoparticles (AuNPs)-conjugated lateral flow immunoassays (LFIA). Using this platform, we quantified five clinically significant cardiovascular biomarkers: Troponin I (cTnI), Creatine Kinase Myocardial Band (CK-MB), N-terminal pro-B-type Natriuretic Peptide (NT-proBNP), D-dimer, and C-reactive Protein (CRP). Standard curves were generated from serial dilutions of known concentrations spiked into fetal bovine serum (FBS). Spectral data were averaged across three replicates and preprocessed using baseline correction and noise reduction techniques. Relative absorbance (ΔA) was calculated by subtracting the absorbance at 680 nm (baseline) from that at 530 nm (peak), minimizing baseline interference and enhancing quantitative accuracy. The platform achieved limits of detection (LOD) as low as 0.0124 ng mL^-1 (cTnI), 0.0342 ng mL^-1 (CK-MB), 0.1422 ng mL^-1 (NT-proBNP), 0.0213 ng L^-1 (D-dimer), and 0.0304 ng L^-1 (CRP) with R² values above 0.98 for all calibration curves. Clinical validation using 47 patient serum samples showed strong agreement with the Abbott Alinity ci-series analyzer (R² > 0.91, r > 0.95). Bland-Altman analysis confirmed consistency within 95% confidence intervals. These results highlight the potential of the proposed novel Point-of-Care (POC) system to deliver fast, reliable and affordable cardiovascular diagnostics in emergency care settings.