Organic Catalytic Activity as a Method for Agnostic Life Detection

An ideal life detection instrument would have high sensitivity but be insensitive to abiotic processes and would be capable of detecting life with alternate molecular structures. In this study, we propose that catalytic activity can be the basis of a nearly ideal life detection instrument. There are several advantages to catalysis as an agnostic life detection method. Demonstrating catalysis does not necessarily require culturing/growing the alien life and in fact may persist even in dead biomass for some time, and the amplification by catalysis is large even by minute amounts of catalysts and, hence, can be readily detected against abiotic background rates. In specific, we propose a hydrolytic catalysis detection instrument that could detect activity in samples of extraterrestrial organic material from unknown life. The instrument uses chromogenic assay-based detection of various hydrolytic catalytic activities, which are matched to corresponding artificial substrates having the same, chromogenic (preferably fluorescent) upon release, group; D- and L-enantiomers of these substrates can be used to also answer the question whether unknown life is chiral. Since catalysis is a time-proportional product-concentration amplification process, hydrolytic catalytic activity can be measured on a sample of even a minute size, and with instruments based on, for example, optofluidic chip technology.

Automated summary

In this study, a nearly ideal life detection instrument based on catalytic activity is proposed, which has high sensitivity but is insensitive to abiotic processes and can detect life with alternate molecular structures. The advantages of catalysis as an agnostic life detection method are demonstrated, including not requiring culturing/growing the alien life and large amplification by catalysis even in dead biomass. A hydrolytic catalysis detection instrument using chromogenic assay-based detection of various hydrolytic catalytic activities is specifically proposed, which can be used to detect activity in samples of extraterrestrial organic material from unknown life.