Biotronics Using Individual Microorganism Cells and Wide Bandgap Semiconductors

The main objective is to interface biological entities, at the cellular level, with III-V semiconductors to enable manipulation of intracellular processes. Very unique and specific manipulation will be the goal of the proposed work via achieving control over interfacial assets (topography, chemistry, charge, stiffness) that can be triggered by the electronic properties of semiconductor materials. As a prototypical entity, the unicellular organism yeast will be used. A multidisciplinary team of biologists, surface materials chemists, and semiconductor growth researchers propose to develop a methodology to manipulate an individual yeast cell placed onto a working semiconductor device, establishing the biotronics paradigm as a complete manipulation loop between biological entity and electronics. This is realized by a response from the yeast that is triggered by external modulation of the interfacial electronic properties without applying external current when the biological entity and the electronic material surface are in contact. The strategy takes advantage of the induced persistent Photoconductivity (PPC) by an external light source in the wide bandgap semiconductor. In this case, the external light source could be an integrated UV laser diode. PPC is due to the accumulation of charge carriers at the semiconductor surface/interface, thus it is a signature of the electronic modification of the semiconductor surface, Figure 1. In turn, the carriers promote the formation of reactive oxygen species on the surface. The presence of oxides, hydroxides and oxyhydroxides can trigger an information response from a biological entity. Interfacial changes can lead to molecular pathway changes that can result in manipulation of cell behavior via the activation/deactivation of targeted metabolic pathways. Subsequently, the information from the biological system will be transferred via the components of the semiconductor device. In general, the biotronics paradigm based on these processes can be represented as in Figure 2, where any possible manipulation of a healthy, functional cell is through ionic chemical pathways, that in turn, are accessed through electronic modulation of the semiconductors. Figure 3 shows a particular implementation of this paradigm. The basic process that relies on an appropriate interface between the yeast and the semiconductor will enable the localization of individual cells and subsequent manipulation of the intracellular processes inside each cell with high specificity with respect to individual cell organelles.