MEMS-Based Enthalpy Arrays

Enthalpy arrays enable label-free detection of a variety of biomolecular interactions, such as protein-ligand binding and enzymatic turnover. Their fabrication using MEMS-technology enables calorimetric measurements at a substantially reduced scale that results in large decreases in the required sample volume compared to conventional microcalorimetry. At the same time, the array format enabled by this miniaturization allows parallel operation to achieve high throughput, making enthalpy arrays a promising tool for proteomics research and drug discovery. This paper focuses on the fabrication of the arrays and presents some recent sensitivity improvements and measurement data: we report an intrinsic noise equivalent temperature difference (NETD) of individual detectors of about 10 muK. Measurement of enzymatic turnover has been successfully demonstrated by phosphorylation of glucose by hexokinase.