Quantum dot enabled lateral flow immunoassay for detection of cardiac biomarker NT-proBNP

Abstract

B-type natriuretic peptide (BNP) is a cardiac-derived neurohormone regulated by intra-cardiac pressure. N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a bio-inert product of BNP production identified as a blood biomarker for diagnosing cardiac distress. Rapid, point-of-care quantification of NT-proBNP concentration is challenging because accurate recognition is often masked by interference of native BNP in blood samples. Recently, monoclonal antibodies have been engineered with high specificity to the tail, i.e. cleaved region, of NT-proBNP; herein, we present a case study using two monoclonal antibodies for NT-proBNP, respectively, as detector and capture antibodies. Using the selected antibodies, we fabricated and characterized a lateral flow immunoassay for NT-proBNP using antibody-labeled quantum dots to improve limit of detection. The reported lateral flow immunoassay exhibited clinically-relevant linear response range: 50–1200 pg mL−1, good stability and repeatability with pooled variance of 8.8% across concentrations of NT-proBNP—highlighting a method for high-resolution, low-cost quantification of NT-proBNP as a point-of-care, single-step diagnostic sensor. Keywords: NT-proBNP, cardiac biomarker, lateral flow, immunoassay, quantum dot