Nano-Sensor for Single Cell Thermal Characterization

A cell’s intracellular temperature has been shown to have a vital role in controlling the cell’s properties, activities and reacting to external stimuli. Yet, current conventional methods are unable to give any measurements when spatial resolution decreases to a micro scale. Many researchers from different fields are trying to develop ways that give high accuracy and high temperature sensitivity. We present a nano-needle microfluidic system for single cell temperature measurement. Here we discuss optimization using the finite element approach to sensor design using tungsten as the electrode and semiconducting metal oxide Co3O4 as the sensing element. The dimensions of the sensor that gave the highest voltage and, thus, the highest sensitivity ratio of 1:4 of the electrode cross sectional area / element diameter, were a gap of 450 nm between the electrodes and a penetration depth of 250 nm of the electrode into the element. Furthermore, the voltage response had a 48 μm difference over a range of 293.15–333.15. The sensor sensitivity was a 0.01° C and the response time was 1 ns.