Array of Interdigitated Bipolar Electrodes for Selective Capture and Analysis of Melanoma Cells

Abstract We report a method for dielectrophoretic capture of melanoma cells and their electrochemical analysis for tumor‐specific markers, using a microfluidic device composed of microwells overlying an array of interdigitated bipolar electrodes (IDBPEs). In this device, cells are captured on each IDBPE by dielectrophoresis, and microfabricated wells allow for retention of the cells to enable their subsequent electrochemical analysis. This advancement is significant because it addresses a need for cancer diagnostics with few‐ to single‐cell resolution amenable to use in low‐resource settings. Specifically, this approach combines the selectivity of dielectrophoresis for cell phenotype, the low cost of electrochemical methods, and the ability of BPEs to be arrayed, with the sensitivity afforded by interdigitation. The IDBPE detects a redox‐active species produced by an enzyme‐linked antibody targeted to a cell surface antigen, and reports the current by electrochemiluminescence. In this work, we first characterize cell capture by dielectrophoresis at the IDBPE array. Second, the retention of cells in the microwells and their viability is demonstrated. Then, the sensitivity of the IDBPE for the redox‐active species is quantified. Finally, we demonstrate capture and analysis of melanoma cells at the IDBPE array, which underscores the ability of the IDBPE to achieve biologically relevant detection limits.