Novel electrochemiluminescent platform based on gold nanoparticles functionalized Ti doped BiOBr for ultrasensitive immunosensing of NT-proBNP.

Highlights • A label-free ECL immunosensor was designed based on Ti doped BiOBr for NT-proBNP detection. • BiOBr was employed as ECL substrate and emitter to simplify the construction process. • The ECL property was further improved by functionalizing BiOBr with Ti and Au NPs. • Sensitive detection of NT-proBNP was achieved with good selectivity and stability. Abstract Heart failure is a serious medical condition and has become one of the world's biggest killers. N-terminal pro-B-type natriuretic peptide (NT-proBNP) has been recommended as a new biomarker of excellent prognosis-predictive ability for heart failure. Herein, a label-free electrochemiluminescence (ECL) immunosensor based on gold nanopariticles (Au NPs) functionalized Ti doped BiOBr (Ti:BiOBr-Au) is fabricated for the detection of NT-proBNP. Firstly, three-dimensional flower-like Ti doped BiOBr (Ti:BiOBr), which is firstly proposed with ECL property, is employed as both the ECL substrate and emitter to simplify the construction procedure. In the presence of K 2 S 2 O 8 , the formed Ti:BiOBr can generate stronger ECL signal than pure BiOBr. Due to the large specific surface area, Ti:BiOBr is functionalized with large amounts of Au NPs to further improve ECL emission. Under optimal experimental conditions, a linear response range for NT-proBNP detection from 0.001 ng mL−1 to 50 ng mL−1 is obtained with a detection limit of 0.33 pg mL−1. Featuring high sensitivity and excellent reproducibility, the proposed ECL immunosensor blazes a novel trail for the sensitive determination of NT-proBNP and other biomarkers. It is worth noting that Ti:BiOBr with stable ECL emission displays tremendous potential in ECL bioanalysis as a novel type of emitter candidates. [ABSTRACT FROM AUTHOR]