Studying cationic exchange in ion-insertion materials for advanced biotechnology applications

Over recent decades, the convergence of microchip technology and biotechnology has fuelled remarkable progress in biosensing and biosynthesis. Notably, the parallelisation of DNA synthesis has substantially reduced the cost of oligonucleotide pools, paving the way for innovative applications such as DNA-based data storage. In addition, significant strides have been made towards fully enzymatic methods for oligonucleotide synthesis. These water-based techniques are not only more cost-effective but also environmentally friendly compared to traditional solvent-based phosphoramidite chemistry. 

At imec, we are pioneering research into the use of ion-intercalation materials (IICMs) to dynamically modulate enzymatic activity on chip. IICMs are highly porous, electrochemically active thin films capable of storing cations during reduction and releasing them upon oxidation. While IICMs are typically utilised in batteries, energy conversion, and electrochemical catalysis, their integration with micro-electrode arrays enables the creation of highly localised cationic gradients. These gradients, in turn, allow for precise spatiotemporal control over the activity of metal-cofactor enzymes, such as DNA polymerases. 

A key challenge arises when multiple cations are present in solution: IICMs are prone to spontaneous cation-exchange. This phenomenon leads to the undesired replacement of specific stored cations (e.g., Mg2+) by others present in the environment (e.g., K+, Na+), prematurely depleting the IICM of the target cation and undermining reliability. 

This internship will focus on investigating the fundamental mechanisms underlying cation-exchange within IICMs and developing effective mitigation strategies. You will employ both electrochemical and biological assays to characterise cation-exchange dynamics and evaluate potential solutions, including: (1) the application of specialised coatings to impart ion selectivity or inhibit diffusion-driven exchange, and (2) the screening of polymerase-compatible monovalent ions that minimise cation-exchange. The internship will be hosted at imec, a leading research institute renowned for its interdisciplinary approach and vibrant international environment. 

This project offers an exciting opportunity to contribute to cutting-edge research at the intersection of materials science, biotechnology, and microelectronics, with significant implications for the future of DNA synthesis and biosensing technologies.