A simple device for protein detection actuated by induced-charge electro-osmotic streaming

Rapid detection of protein analytes using antibody microarray is significant, which can be engineered in the diagnosis of infectious diseases, and detection of bacteria. For this, we take advantage of induced-charge electro-osmotic (ICEO) streaming to develop a microfluidic device to accomplish detection of proteins. Open bipolar electrode (OBPE) linear array is designed on the microchannel bottom to stimulate ICEO rolls, and columns are designed uniformly on the cover plate to immobilize the capture antibody. After installing the cover plate on the detection chamber, columns are repositioned in the action range of ICEO streaming. In such configuration, ICEO streaming can transport proteins towards microcolumns to enrich the protein analyte and extend interaction time between capture antibody and proteins. We first investigate the influence of the columns on the development of ICEO streaming and flow-rate distribution in the model with an OBPE. Then, enrichment effect of ICEO streaming on protein analyte is explored, and the detection capability is validated. Afterward, we increase the number of OBPEs and microcolumns to study the performance and parametric dependence of this method in the large-scale detection of proteins. Furthermore, a 3D computational model is established to investigate the spatial distribution of flow field, protein concentration, and dynamic detection process. Finally, we demonstrate the enhancement mechanism of ICEO streaming on the protein detection, and characterize detection performance of this technique. This chip is inexpensive and portable, which holds good potential to be a useful tool in the detection and analysis of protein analytes for disease diagnosis.