Photochemically Driven Peptide Formation in Supersaturated Aerosol Droplets.

The condensation of amino acids into peptides plays a crucial role in protein synthesis and is thus essential for understanding the origins of life. However, the spontaneous formation of peptides from amino acids in bulk aqueous media is energetically unfavorable, posing a challenge for elucidating plausible abiotic mechanisms. In this study, we investigate the formation of amide bonds between amino acids within highly supersaturated aerosol droplets containing dicyandiamide (DCD), a cyanide derivative potentially present on primordial Earth.

Temperature-Controlled Dual-Beam Optical Trap for Single Particle Studies of Organic Aerosol.

An optical trapping cell that is capable of suspending particles using two counter-propagating beams in a temperature-controlled environment is reported here. With this dual-beam optical trap, we are able to hold single micron-sized droplets at temperatures down to 253 K (-20 °C) for hours at a time and in metastable (supercooled) states. As particles are trapped at the shared focal points of two intense beams, strong cavity-enhanced Raman scattering (CERS) is observed and allows for high precision measurements of physical properties.