An immunomodified magneto-surface stress-electrical coupling biosensor for detection of NT-proBNP

Integrates FeGa magnetostrictive effect to eliminate gravity induced interference and amplify film deformation for enhanced biosensor sensitivity. • Employs detection antibody based dual signal amplification, achieving a low NT-proBNP LOD of 0.01 pg/mL in PBS. • Exhibits stable linear ranges (0.01–1.5 pg/mL and 1.6–15 pg/mL) and high recoveries (96%–106%) in pooled saliva. • This product exhibits excellent anti-interference performance and long-term stability for non-invasive heart failure diagnosis. While the low concentration of salivary N-terminal pro-B-type natriuretic peptide (NT-proBNP) has hindered its use in early diagnosis and monitoring of heart failure (HF), its non-invasiveness and convenience are favored by many. In this study, a biosensor based on multi field coupling and sandwich immunoassay with matched capture and detection antibodies has been developed for high-sensitivity detection of NT-proBNP. Based on the magnetostrictive effect of Fe Ga alloy under magnetic field, the gravity interference of the sensitive layer in traditional sensors is eliminated, the deformation of the thin film is amplified, and the sensitivity of the sensor is improved. In addition, by adding detection antibodies to achieve secondary binding of antigens and antibodies, the surface stress is further amplified, reducing the detection limit of the sensor to 0.01 pg/mL. In addition, the accurate detection of NT-proBNP in pooled saliva samples (PSS) indicates that the prepared biosensor has good practicality. All these results show that the multi field coupling and the dual-antibody sandwich strategy contributes to improving the performance of the biosensors and provides a platform for high-sensitivity detection of clinical biomarkers. Download: Download high-res image (144KB) Download: Download full-size image