1 research outputs found
High-Density Droplet Microarray of Individually Addressable Electrochemical Cells
Microarray technology
has shown great potential for various types
of high-throughput screening applications. The main read-out methods
of most microarray platforms, however, are based on optical techniques,
limiting the scope of potential applications of such powerful screening
technology. Electrochemical methods possess numerous complementary
advantages over optical detection methods, including its label-free
nature, capability of quantitative monitoring of various reporter
molecules, and the ability to not only detect but also address compositions
of individual compartments. However, application of electrochemical
methods for the purpose of high-throughput screening remains very
limited. In this work, we develop a high-density individually addressable
electrochemical droplet microarray (eDMA). The eDMA allows for the
detection of redox-active reporter molecules irrespective of their
electrochemical reversibility in individual nanoliter-sized droplets.
Orthogonal band microelectrodes are arranged to form at their intersections
an array of three-electrode systems for precise control of the applied
potential, which enables direct read-out of the current related to
analyte detection. The band microelectrode array is covered with a
layer of permeable porous polymethacrylate functionalized with a highly
hydrophobic–hydrophilic pattern, forming spatially separated
nanoliter-sized droplets on top of each electrochemical cell. Electrochemical
characterization of single droplets demonstrates that the underlying
electrode system is accessible to redox-active molecules through the
hydrophilic polymeric pattern and that the nonwettable hydrophobic
boundaries can spatially separate neighboring cells effectively. The
eDMA technology opens the possibility to combine the high-throughput
biochemical or living cell screenings using the droplet microarray
platform with the sequential electrochemical read-out of individual
droplets