Modeling of Dielectrophoresis for Myoglobin Molecules in a Microchannel With Parallel Electrodes

Myoglobin is one of the important cardiac markers, whose concentration increases from 90 pg/ml to over 5000 pg/ml in the blood serum of heart attack patients. Separation and detection of myoglobin play a vital role in deciding the cardiac arrest in advance, which is the challenging part of ongoing research. In the present study, one of the electrokinetic approach i.e., dielectrophoresis (DEP) is chosen to manipulate the myoglobin molecule in aqueous solution. A generalized theoretical expression is developed for the dielectrophoretic force acting on an arbitrary shape of the particle. Dielectric myoglobin model is developed by approximating the shape of the molecule as sphere, oblate and prolate spheroids. Mathematical model for simulating dielectrophoretic behavior of a myoglobin molecule in a microchannel is developed. The microchannel consists of parallel array of electrodes at the bottom wall. Finite element based approach is considered to solve the problem. The variation in the Clausius-Mossotti factor with respect to the applied electric field frequency is observed for aqueous solution of myoglobin. The crossover frequency is obtained as 30 MHz for given properties, for all the shapes of molecule. Shifting of crossover frequency with conductivity of medium is observed. The simulation results indicate that, the electric field and DEP forces are maximum at the edges of the electrodes and minimum elsewhere. The results also indicate that, DEP force exponentially decayed along the height of the channel.