Thermal Detection of Cardiac Biomarkers Heart-Fatty Acid Binding Protein and ST2 Using a Molecularly Imprinted Nanoparticle-Based Multiplex Sensor Platform

This manuscript describes the production of molecularly imprinted polymer nanoparticles (nanoMIPs) for the cardiac biomarkers heart-fatty acid binding protein (H-FABP) and ST2 by solid-phase synthesis, and their use as synthetic antibodies in a multiplexed sensing platform. Analysis by surface plasmon resonance (SPR) shows that the affinity of the nanoMIPs is similar to that of commercially available antibodies. The particles are coated onto the surface of thermocouples and inserted into 3D-printed flow cells of different multiplexed designs. We demonstrate that it is possible to selectively detect both cardiac biomarkers within the physiologically relevant range. Furthermore, the developed sensor platform is the first example of a multiplex format of this thermal analysis technique which enables simultaneous measurements of two different compounds with minimal cross selectivity. The format where three thermocouples are positioned in parallel exhibits the highest sensitivity, which is explained by modeling the heat flow distribution within the flow cell. This design is used in further experiments and proof-of-application of the sensor platform is provided by measuring spiked fetal bovine serum samples. Because of the high selectivity, short measurement time, and low cost of this array format, it provides an interesting alternative to traditional immunoassays. The use of nanoMIPs enables a multimarker strategy, which has the potential to contribute to sustainable healthcare by improving the reliability of cardiac biomarker testing.