An instrument design for non-contact detection of biomolecules and minerals on Mars using fluorescence

Abstract

We discuss fluorescence as a method to detect polycyclic aromatic hydrocarbons and other organic molecules, as well as minerals on the surface of Mars. We present an instrument design that is adapted from the ChemCam instrument which is currently on the Mars Science Lander Rover Curiosity and thus most of the primary components are currently flight qualified for Mars surface operations, significantly reducing development costs. The major change compared to ChemCam is the frequency multipliers of the 1064 nm laser to wavelengths suitable for fluorescence excitation (266 nm, 355 nm, and 532 nm). We present fluorescence spectrum for a variety of organics and minerals relevant to the surface of Mars. Preliminary results show minerals already known on Mars, such as perchlorate, fluoresce strongest when excited by 355 nm. Also we demonstrate that polycyclic aromatic hydrocarbons, such as those present in Martian meteorites, are highly fluorescent at wavelengths in the ultraviolet (266 nm, 355 nm), but not as much in the visible (532 nm). We conclude that fluorescence can be an important method for Mars applications and standoff detection of organics and minerals. The instrument approach described in this paper builds on existing hardware and offers high scientific return for minimal cost for future missions.

Graphene and silicene quantum dots for nanomedical diagnostics

“…The results obtained for pyrene are in good agreement with experimental measurements. 51,52 It is worth noting that the anisotropic behaviour of the optical properties of QDs observed in ref. 39 and 49 disappear under the edges functionalization with OH, CH 3 and COOH.…”

Phototrophic microbes form endolithic biofilms in ikaite tufa columns (SW Greenland)

“…However, fluorescence emission below ∼700 nm was not observed in samples when exited in the spectral ranges used here, i.e., 450–492 nm and 515–560 nm (Smith et al . ), and interferences between carbonate and photopigment fluorescence were thus not observed. Obvious ‘false signal’ due to reflectances from the aquarium glass and metal stands holding the ikaite column in place, were deleted from the original Canon RAW fluorescence images recorded under blue and green excitation.…”

Detecting Kerogen as a Biosignature Using Colocated UV Time-Gated Raman and Fluorescence Spectroscopy

“…The rapidly approaching Mars 2020 mission brings about a crucial need to better understand the capabilities of Raman and fluorescence instruments to identify biosignatures in realistic, natural, and complex Mars analog samples. Recent work has demonstrated the capabilities of UV Raman and fluorescence instruments for biosignature detection on Mars (e.g., Smith et al, 2014), including those that form the foundation of the SHERLOC instrument (Beegle et al, 2014(Beegle et al, , 2015(Beegle et al, , 2016Abbey et al, 2017) and the foundation of the UV system used here (Eshelman et al, 2014(Eshelman et al, , 2015Skulinova et al, 2014). However, these previous studies investigated synthetic, pure, or extracted and concentrated organics, or mineral powders spiked with organic molecules, and they do not take into account complex interactions of mixed-phase, fossilized organics interacting with their host matrix, as found in nature.…”