A Novel High-Sensitivity Cardiac Multibiomarker Detection System Based on Microfluidic Chip and GMR Sensors

We have developed a novel cardiac multibiomarker detection system, wherein cardiac biomarkers NT-proBNP and cTnI could be detected simultaneously in 20 min. The lower limits of detection of NT-proBNP and cTnI were 0.33 and 1.43 pg/ml, respectively. Furthermore, based on a microfluidic chip and a giant magnetoresistance sensor, the detecting system was realized in a small platform to decrease the manufacturing cost and the difficulty of operation. In addition, owing to the usage of the superparamagnetic nanoparticles of suitable diameter and bovine serum albumin blocker in nanoparticles solution, the system achieved a high signal-to-noise ratio in the whole dynamic range. This magnetic immunoassay system can be adapted to detect a variety of clinically important biomolecules in human samples and provide accurate information to diagnose human diseases.