Mid-infrared absorption spectroscopy is a powerful tool for optically probing the molecular structure of biological samples. However, using conventional approaches, IR measurements on small quantities of molecules are extremely challenging due to sensitivity limitations. The strong IR absorption of liquid water presents additional obstacles to performing measurements in biomolecules' native, aqueous environments. In this review we discuss the application of engineered plasmonic nanoantennas to overcoming these challenges. We provide overviews and highlight the key concepts of our recent work in designing infrared antennas and applying them to enhance the absorption of minute quantities of biomolecules as well as new fabrication methods for their high throughput and low-cost manufacturing.