DNA Purification-on-a-chip via electrified polarization of nanostructures

DNA purification is a cornerstone of modern molecular biology, enabling applications ranging from clinical diagnostics and infectious disease surveillance to environmental monitoring, food safety, and precision medicine. The growing demand for rapid, portable, and automated genetic analysis has accelerated the development of lab-on-a-chip technologies capable of integrating sample preparation with downstream detection. However, DNA purification remains one of the most challenging steps to miniaturize. State-of-the-art microfluidic purification methods typically rely on silica membranes, magnetic beads, or chemically functionalized surfaces that selectively bind nucleic acids under specific buffer conditions. While effective, these approaches often require disposable materials, multiple reagent exchanges, and complex fluidic handling, limiting scalability and integration into fully autonomous devices. Electrically controlled DNA capture offers an attractive alternative by using electrode polarization to manipulate nucleic acid adhesion directly, potentially enabling reagent-efficient purification with active electronic control over each processing step [1,2].

This PhD project will investigate electrically-driven DNA purification through reversible electroadhesion mechanisms. The research will examine how electrode polarization can attract and retain negatively charged DNA molecules during capture and washing, while allowing contaminants such as proteins, salts, and other matrix components to be removed. A systematic comparison of planar metal electrodes, metal oxides, and electrodes coated with dielectric or solid-electrolyte layers will be conducted to identify materials and polarization conditions that maximize DNA recovery while minimizing non-specific adsorption. Subsequently, mechanisms for DNA release will be explored through reverse polarization as well as electrochemically induced surface conversion reactions. The most promising capture-release strategy will then be transferred to nanostructured electrode architectures and integrated in a standalone device. The final objective is to establish a purification-on-a-chip platform that combines sample introduction, DNA capture, washing, controlled release, and collection within a single miniaturized device, providing a foundation for compact and highly integrated genetic analysis systems.