Detection of Biological Bricks in Space. The Case of Adenine in Silica Aerogel

Abstract

Space missions using probes to return dust samples are becoming more frequent. Dust collectors made of silica aerogel blocks are used to trap and bring back extraterrestrial particles for analysis. In this work, we show that it is possible to detect traces of adenine using surface-enhanced Raman spectroscopy (SERS). The method was first optimized using adenine deposition on glass slides and in glass wells. After this preliminary step, adenine solution was injected into the silica aerogel. Finally, gaseous adenine was successfully trapped in the aerogel. The presence of traces of adenine was monitored by SERS through its characteristic bands at 732, 1323, and 1458 cm−1 after the addition of the silver Creighton colloid. Such a method can be extended in the frame of Tanpopo missions for studying the interplanetary transfer of prebiotic organic compounds of biological interest.

Generation and Regeneration of the C(sp3)–F Bond and 1,4-NADH/NADPH via Newly Designed S-gC3N4@Fe2O3/LC Photocatalysts under Solar Light

“…The generation of 1,4-NADH/NADPH can be expediently followed by scrutinizing the emergence of the absorbance at wavelength 340 nm, identifying the 1,4-NADH/NADPH amount (concentration or % of 1,4-NADH/NADPH) of the corresponding solution. As per the reported paper, − NAD + /NADP + and 1,4-NADH/NADPH strongly absorb ultraviolet (UV) light due to the existence of an adenine ring. The absorption peaks of NAD + /NADP + and 1,4-NADH/NADPH are located at 259 and 340 nm along with extinction coefficients of 16900 and 6220 M –1 cm –1 .…”

Surface-Enhanced Raman Spectroscopy (SERS) for Identifying Traces of Adenine in Organic-Bearing Extraterrestrial Dust Analogs Captured in the Tanpopo Aerogel after Hypervelocity Impacts

“…Even when doped with a very dilute solution (5•10 −9 mol/L), adenine was clearly detected in the dusts. The band at 730 cm −1 was attributed to a breathing mode, and the multi-component band at 1330 cm −1 to mixed in-plane stretching vibrations of the six-membered ring [27].…”

“…Silver Creighton colloids were used to amplify the Raman signal [25]. This method has already been successfully used to detect the adenine adsorbed on Zagami, a Martian meteorite, and on Murchison, on montmorillonite samples, and also trapped directly in silica aerogel [20,26,27].…”