The Bioelectronics group currently has openings for Bachelor and Master projects. Our research employs microfabrication to create liquid-filled, nanometer-scale channels and electrodes with which small numbers of molecules (and even single molecules) are detected and manipulated by electrical means. This enables both fundamental experiments on the physics and chemistry of ionic systems on the nanometer scale, and allows us to explore the ultimate limits of electrical detection for (bio)sensor applications.
Our research is interdisciplinary and we welcome students from all study programs with an interest in our topics. Do keep in mind, however, that much of our work includes a significant component of physics and/or physical chemistry, being at the interface between the physics of fluids, electrochemistry and condensed matter.
Below are a number of specific projects that are currently available. This list can fluctuate quickly, however: this is exploratory research and surprises do happen! To further explore possibilities, please contact Prof. Serge Lemay (email@example.com) for an appointment.
AC transport properties of single conducting polymers
We are exploring a new electronic transduction mechanism for biosensing based on the detection of single conducting polymer molecules that are freely diffusing in solution. Conducting polymers are materials of great interest in printable electronics, solar cells and OLEDs, but their use in sensors is in its infancy. Here we employ pairs of electrodes separated by about 10 nm to probe the electronic transport properties of single polymer chains. Each molecule works as a nanoscopic telegraph, effectively closing a switch every time that it touches both electrodes. We have so far has focused solely on measuring the DC transport properties of the molecules, but we expect that measuring AC currents instead can improve the signal-to-noise ratio of our sensors. In this project, we will use lock-in detection to probe this hypothesis experimentally. This combines precision electronic measurements and single-molecule field-effect transistors for sensitive detection in liquid.
Current blockade electrochemical sensors
In current blockade sensors, single micro- or nanosized objects are detected when they interfere with an electrochemical reaction taking place at an electrode (basically the particles get in the way of molecules trying to diffuse to the electrode). A drawback of this method, however, is that particles give a different response depending on whether they hit the electrode near the edge or near its center, greatly limiting the ability to differentiate between different types of particles. In this project we will attempt to overcome this limitation by developing electrodes in the form of thin (nanoscale) disks. The project will involve the microfabrication of prototype electrodes in the NanoLab cleanroom and assessing their performance through electrical measurements in liquid.
DARK-FIELD Scattering microscopy for probing charge injection in liquid
Scattering microscopy is an emerging optical technique in nanoscience in which the ability of modern cameras to detect minute changes in light intensity is used to probe microscopic phenomena. In this project, we aim to probe the physics of what happens when charge is injected into a liquid via a microscale electrode. Changes in the local distribution of ions will be detected optically. This process couples fluid mechanics with electrochemistry, a largely unexplored area. This is a new research line within the group and the research at present has a fundamental character.