Trapping magnetic nanoparticles for in-line capillary electrophoresis in a liquid based capillary coolant system

A method to trap magnetic nanoparticles inside the electrophoretic capillary has been developed without disabling and disturbing the coolant liquid recirculation. The complete optimization from setting up of the external magnetic field to injecting the magnetic nanoparticles in order to facilitate efficient trapping is described. In addition to this, the setup has been tested with 150mM sodium phosphate buffer as the background electrolyte at different pH values (2, 4, 6 and 8). All these pH values have been investigated at 25°C and 37°C to mimic room temperature and physiological temperature, respectively. The capture of magnetic nanoparticles was examined via UV detection and also microscopically. To demonstrate the efficiency of the trapping, an in-line capillary electrophoresis enzymatic assay using hFMO3 was performed successfully. This method can be of further use for in-line capillary electrophoresis using magnetic nanoparticles as a solid support for enzyme/protein immobilization.