Microscale calorimetric device for determining reaction parameters

- Two microcalorimeter designs based on Nanohole Array Sensors are described.
- Proof that Nanohole Array Sensors respond to thermal effects from reactions.
- The use of thermodynamic properties in the drug discovery process is reviewed.
- Results from dilution experiments are analyzed and compared to literature values.
- Ethanol-water experimental results are within 5% (co-flow) and 1.3% (chamber).

Two microscale calorimeter designs based on nanohole array sensors are described. These devices use significantly less compound, are significantly smaller and require less time to perform calorimetric experiments which make them attractive to the drug discovery process. They also have the potential for high throughput screening which would provide key information earlier in the drug discovery process and for multiplexing experiments. The described device is a departure from the calorimeters, ITC and DSC, currently being used. The devices tested were used to measure the thermodynamic property, Enthalpy of reaction or dilution, using the observed change in the extraordinary optical transmission, EOT, through a nanohole array sensor. Experiments that confirm that the observed EOT changes are related to the thermal effects of the reaction are provided. Preliminary results indicate that the device can determine the concentration changes in a water-ethanol dilution experiment and the Enthalpy of dilution to within 1.3%. A relative comparison of the enthalpy of reaction at different reactant concentrations for the co-flow configuration of the device are within 5% of those predicted using literature values. Means of processing the observed EOT to eliminate unwanted fringe behaviors are discussed and illustrate the close agreement between thermistor and EOT thermal responses.