Nano-calorimetry of small-sized biological samples

A miniaturized calorimeter with a signal noise of less than 10 nW is presented for the first time. The outstanding signal performance was obtained due to an elaborated temperature control inside the system. With a sample volume of around 6 μl a specific heat flow detection limit of <2 mW l−1 was achieved, which is a prerequisite for promising microbiological applications. The performance of the new calorimeter is demonstrated by investigations of the metabolic heat production of biofilms, bacteria cultured in suspensions, and single fish embryos.