Ultrafast synthesis of AgNP-based plasmonic film for multiplexed detection of heart failure biomarkers

The high morbidity and mortality rates of heart failure remain a challenge to global health. B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are important biomarkers for accurate diagnosis of heart failure. Herein, we construct a new surface-enhanced Raman scattering (SERS) platform by integrating a silver nanoparticle (AgNP)-based plasmonic film with exonuclease I (Exo I)-driven recycling amplification for simultaneous monitoring of BNP and NT-proBNP. The AgNP-based plasmonic film is rapidly synthesized within 2 min with an interfacial self-assembly strategy. The presence of BNP and NT-proBNP can activate Exo I-driven recycling amplification, liberating numerous TAMRA and Cy3 molecules which can be quantified by AgNP-based plasmonic film-mediated SERS, with TAMRA indicating BNP and Cy3 indicating NT-proBNP. Taking advantage of excellent SERS activity of AgNP-based plasmonic film and high amplification efficiency of Exo I-driven recycling amplification, this SERS platform possesses good specificity and high sensitivity with a limit of detection of 8.7 fg/mL for BNP and 10 fg/mL for NT-proBNP, and it can discriminate BNP and NT-proBNP level in clinical blood samples from healthy participants and heart failure patients. Moreover, this SERS platform can be extended to detect other important biomarkers (e.g., miRNAs and enzymes) by simply changing the specific recognition sequences of probes, holding promising applications in clinical diagnosis and precise therapy.