In this article, we describe a novel straightforward method for the specific identification of viable cells (macrophages and cancer cell lines MCF-7 and Jurkat) in a buffer solution. The detection of the various cell types is based on changes of the heat transfer resistance at the solid-liquid interface of a thermal sensor device induced by binding of the cells to a surface-imprinted polymer layer covering an aluminum chip. We observed that the binding of cells to the polymer layer results in a measurable increase of heat transfer resistance, meaning that the cells act as a thermally insulating layer. The detection limit was found to be on the order of 10(4) cells/mL, and mutual cross-selectivity effects between the cells and different types of imprints were carefully characterized. Finally, a rinsing method was applied, allowing for the specific detection of cancer cells with their respective imprints while the cross-selectivity toward peripheral blood mononuclear cells was negligible. The concept of the sensor platform is fast and low-cost while allowing also for repetitive measurements.