Submicron sensors of local electric field with single-electron resolution at room temperature

We describe probes of a local electric field, which are capable of detecting an electric charge as small as the charge of one electron e, operational under ambient conditions and having a spatial resolution down to 100nm. The submicron-sized probes were made from a high-density high-mobility two-dimensional electron gas, which is sensitive to the presence of electric charges near its surface. We demonstrate the possibility of using such microprobes for life-science applications by measuring an electric response of individual yeast cells to abrupt changes in their environment.