Bio-Instrument aims to bring life to other planets | Research & Technology | Jul 2022
HONOLULU, July 11, 2022 – The Compact Color Biofinder, an imaging device developed by researchers at the University of Hawai’i at Manoa, has demonstrated its ability to detect biofluorescence signals from traces of organic matter at a distance of a few centimeters to 5 M. According to Sonia Rowley, a biologist with the Biofinder development team, the capabilities of the device allow precise and non-invasive detection of contaminants such as microbes or extraterrestrial biohazards that come from or towards Earth.
The Biofinder’s capabilities would be critical to NASA’s planetary protection program, Rowley said.
Since 2012, a team has been working on the preparation of the Biofinder to rapidly detect biological materials in the context of planetary exploration and the search for extraterrestrial life, living or extinct. The Biofinder is a portable instrument that works with a 24 V battery and a laptop computer. It uses a compact, solid-state, conduction-cooled Nd:YAG pulsed laser that provides two simultaneous wavelengths, 355 nm and 532 nm, for fluorescence excitation.
Most biological materials, for example amino acids, fossils and bioresidues, have strong fluorescence signals with lifetimes less than 20 ns. The Biofinder detects the fluorescence of organic materials and locates them over a large area at a video speed of 20 fps. The video speed is synchronized with the laser repetition rate of 20 pulses per second.
To record short-lived fluorescence signals from organic and biological materials, the Biofinder detector is triggered for its shortest exposure time, which is 1 µs. A short detection time is useful for blocking out long-lived mineral phosphorescence signals and background noise.
Biometer detection of biological residues in a fish fossil: (a) white light image of a fish fossil from the Green River Formation; (b) fluorescence image of the fish fossil obtained by the Biofinder. Courtesy of Misra et al., 2022.
The Biofinder has also demonstrated its ability to distinguish between mineral phosphorescence and organic fluorescence from standoff distances under daylight conditions and within short measurement times. The Biofinder distinguishes between different types of organic materials by taking color images.
“Currently, no other equipment can detect minute amounts of bioresidue on a rock during daytime,” said Anupam Misra, chief instrument developer and researcher at the Institute of Geophysics and Planetology of Hawaii at the University of Hawaii. Manoa School of Ocean and Earth Science and Technology.
The researchers used fossils from the Green River Formation, a fossil bed tens of millions of years old, to test the instrument’s ability to detect biomarkers in long-extinct species. The Biofinder examined 35 specimens of fish fossils in their original rock matrix from a distance of 50cm to look for signs of biological remains.
Fluorescence images taken by the Biofinder instrument showed that fish fossils analyzed in the Green River Formation (Eocene period, 56.0 million to 33.9 million years ago) still contain considerable amounts of biological residue.
The researchers used spectroscopic and microscopic methods to confirm the results of the Biofinder fluorescence imaging.
The researchers said that fluorescence microscopes and examination under UV light have been used in the past to study fossils, but these methods have difficulty performing in situ detection in daylight and are unable to eliminate interference from mineral phosphorescence signals. “The Biofinder works at a distance of several meters, takes video and can quickly scan a large area,” Misra said.
These capabilities could help an exploration rover identify objects of interest in the search for life beyond Earth. Characterization techniques, such as Raman spectroscopy or laser-induced fracture spectroscopy, could then be used to determine the molecular and elemental composition of selected objects.
“If the Biofinder were mounted on a rover on Mars or another planet, we would be able to quickly scan large areas for evidence of past life, even if the organism was small, not easy to see with our eyes. and dead for many millions of years,” Misra said.
Misra and his colleagues ask for the opportunity to send the Biofinder on a NASA mission.
The research has been published in Scientific reports (www.doi.org/10.1038/s41598-022-14410-8).