Multifunctionalized Particles for Biosensor Use

The mass sensitive sedimentation subtechnique of FFF differs from the flow analogue in two principal ways: Firstly, resolution in sdFFF varies with analyte size to the third power – compared to the first power size dependence for the flow system. Secondly, conversion of sdFFF retention data into mass or size information for the analyte requires knowledge of its density, a quantity that has to be determined separately. Since no such input parameter is required to extract size information from flow FFF data, the sedimentation analogue has obtained a reputation for being less “universal” than its flow counterpart. The present article intends to demonstrate some of the advantages offered by the high mass sensitivity of the sdFFF technique, especially in the design and optimization of bioanalytical processes involving nanoparticles.