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HCN polymers are a group of complex and heterogeneous substances that are widely known in the fields of astrobiology and prebiotic chemistry. In addition, they have recently received considerable attention as potential functional material coatings. However, the real nature and pathways of formation of HCN polymers remain open questions. It is well established that the tuning of macromolecular structures determines the properties and practical applications of a polymeric material. Herein, different synthetic conditions were explored for the production of HCN polymers from NHCN or diaminomaleonitrile in aqueous media with different concentrations of the starting reactants and several reaction times. By using a systematic methodology, both series of polymers were shown to exhibit similar, but not identical, spectroscopic and thermal fingerprints, which resulted in a clear differentiation of their morphological and electrochemical properties. New macrostructures are proposed for HCN polymers, and promising insights are discussed for prebiotic chemistry and materials science on the basis of the experimental results.

The conditions for the potential abiotic formation of organic compounds from inorganic precursors have great implications for our understanding of the origin of life on Earth and for its possible detection in other environments of the Solar System. It is known that aerosol-interfaces are effective at enhancing prebiotic chemical reactions, but the roles of salinity and pH have been poorly investigated to date. Here, we experimentally demonstrate the uniqueness of alkaline aerosols as prebiotic reactors that produce an undifferentiated accumulation of a variety of multi-carbon biomolecules resulting from high-energy processes (in our case, electrical discharges). Using simulation experiments, we demonstrate that the detection of important biomolecules in tholins increases when plausible and particular local planetary environmental conditions are simulated. A greater diversity in amino acids, carboxylic acids, N-heterocycles, and ketoacids, such as glyoxylic and pyruvic acid, was identified in tholins synthetized from reduced and neutral atmospheres in the presence of alkaline aqueous aerosols than that from the same atmospheres but using neutral or acidic aqueous aerosols.ols.

The Atacama Desert, the oldest and driest desert on Earth, displays significant rains only once per decade. To investigate how microbial communities take advantage of these sporadic wet events, we carried out a geomicrobiological study a few days after a heavy rain event in 2015. Different physicochemical and microbial community analyses were conducted on samples collected from playas and an alluvial fan from surface, 10, 20, 50, and 80 cm depth. Gravimetric moisture content peaks were measured in 10 and 20 cm depth samples (from 1.65 to 4.1% w/w maximum values) while, in general, main anions such as chloride, nitrate, and sulfate concentrations increased with depth, with maximum values of 13–1,125; 168–10,109; and 9,904–30,952 ppm, respectively. Small organic anions such as formate and acetate had maximum concentrations from 2.61 to 3.44 ppm and 6.73 to 28.75 ppm, respectively. Microbial diversity inferred from DNA analysis showed Actinobacteria and Alphaproteobacteria as the most abundant and widespread bacterial taxa among the samples, followed by Chloroflexi and Firmicutes at specific sites. Archaea were mainly dominated by Nitrososphaerales, Methanobacteria, with the detection of other groups such as Halobacteria. Metaproteomics showed a high and even distribution of proteins involved in primary metabolic processes such as energy production and biosynthetic pathways, and a limited but remarkable presence of proteins related to resistance to environmental stressors such as radiation, oxidation, or desiccation. The results indicated that extra humidity in the system allows the microbial community to repair, and prepare for the upcoming hyperarid period. Additionally, it supplies biomarkers to the medium whose preservation potential could be high under strong desiccation conditions and relevant for planetary exploration.

[EN] Potential martian molecular targets include those supplied by meteoritic carbonaceous chondrites such as amino acids and polycyclic aromatic hydrocarbons and true biomarkers stemming from any hypothetical martian biota (organic architectures that can be directly related to once living organisms). Heat extraction and pyrolysis-based methods currently used in planetary exploration are highly aggressive and very often modify the target molecules making their identification a cumbersome task. We have developed and validated a mild, nondestructive, multiplex inhibitory microarray immunoassay and demonstrated its implementation in the SOLID (Signs of Life Detector) instrument for simultaneous detection of several nonvolatile life- and nonlife-derived organic molecules relevant in planetary exploration and environmental monitoring. By utilizing a set of highly specific antibodies that recognize D- or L- aromatic amino acids (Phe, Tyr, Trp), benzo[a]pyrene (B[a]P), pentachlorophenol, and sulfone-containing aromatic compounds, respectively, the assay was validated in the SOLID instrument for the analysis of carbon-rich samples used as analogues of the organic material in carbonaceous chondrites or even Mars samples. Most of the antibodies enabled sensitivities at the 1-10ppb level and some even at the ppt level. The multiplex immunoassay allowed the detection of B[a]P as well as aromatic sulfones in a water/methanol extract of an Early Cretaceous lignite sample (c.a., 140 Ma) representing type IV kerogen. No L- or D-aromatic amino acids were detected, reflecting the advanced diagenetic stage and the fossil nature of the sample. The results demonstrate the ability of the liquid extraction by ultrasonication and the versatility of the multiplex inhibitory immunoassays in the SOLID instrument to discriminate between organic matter derived from life and nonlife processes, an essential step toward life detection outside Earth.

The kinetics of the reaction of the synthesis of HCN polymers in aqueous medium at high temperatures have been analysed to ascertain a suitable model for this material, for which it was recently demonstrated that prebiotic chemistry may now be adapted in the development of a new generation of high performance coatings and adhesives with biomedical applications. These experimental conditions were chosen for the simplicity of the reagents, being particularly convenient in regard to potential industrial scale-up of coating technology, where these polymers have revealed an interesting field of application. The kinetics of the precipitation polymerization of HCN in water were studied under isothermal conditions at four different temperatures between 75 °C and 90 °C throughout gravimetric measurements. The use of the Kamal–Sourour autocatalytic kinetic model was proposed, properly describing the overall formation process of this insoluble HCN polymer. All of the kinetic parameters, including reaction orders, kinetic constants and activation energy, were determined for the cross-linking polymerization reaction under study, and a relevant autocatalysis effect was observed. An isoconversion method was also used to analyse the variation of the global activation energy with conversion; and characterization by means of elemental analysis, Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM) was carried out. This study demonstrates the autocatalytic, robust and straightforward character of this heterogeneous aqueous HCN polymerization, and to the best of our knowledge, this report describes the first time that a systematic and extended kinetic analysis has been conducted to obtain a more comprehensive and deeper understanding of this complex reaction, which is of great interest to the origin of life and, currently, to materials science.

HCN polymerization is one of the most important and fascinating reactions in prebiotic chemistry, and interest in HCN polymers in the field of materials science is growing. However, little is known about the kinetics of the HCN polymerization process. In the present study, a first approach to the kinetics of two sets of aqueous HCN polymerizations, from NH4CN and NaCN, at middle temperatures between 4 and 38 °C, has been carried out. For each series, the presence of air and salts in the reaction medium has been systematically explored. A previous kinetic analysis was conducted during the conversion of the insoluble black HCN polymers obtained as gel fractions in these precipitation polymerizations for a reaction of one month, where a limit conversion was achieved at the highest polymerization temperature. The kinetic description of the gravimetric data for this complex system shows a clear change in the linear dependence with the polymerization temperature for the reaction from NH4CN, besides a relevant catalytic effect of ammonium, in comparison with those data obtained from the NaCN series. These results also demonstrated the notable influence of air, oxygen, and the saline medium in HCN polymer formation. Similar conclusions were reached when the sol fractions were monitored by UV–vis spectroscopy, and a Hill type correlation was used to describe the polymerization profiles obtained. This technique was chosen because it provides an easy, prompt and fast method to follow the evolution of the liquid or continuous phase of the process under study.

Potential martian molecular targets include those supplied by meteoritic carbonaceous chondrites such as amino acids and polycyclic aromatic hydrocarbons and true biomarkers stemming from any hypothetical martian biota (organic architectures that can be directly related to once-living organisms). Heat extraction and pyrolysis-based methods currently used in planetary exploration are highly aggressive and very often modify the target molecules, making their identification a cumbersome task. We have developed and validated a mild, nondestructive, multiplex inhibitory microarray immunoassay and demonstrated its implementation in the SOLID (Signs of Life Detector) instrument for simultaneous detection of several nonvolatile life- and nonlife-derived organic molecules relevant in planetary exploration and environmental monitoring. By utilizing a set of highly specific antibodies that recognize D- or L-aromatic amino acids (Phe, Tyr, Trp), benzo[a]pyrene (B[a]P), pentachlorophenol, and sulfone-containing aromatic compounds, respectively, the assay was validated in the SOLID instrument for the analysis of carbon-rich samples used as analogues of the organic material in carbonaceous chondrites or even Mars samples. Most of the antibodies enabled sensitivities at the 1–10 ppb level and some even at the part-per-trillion level. The multiplex immunoassay allowed the detection of B[a]P as well as aromatic sulfones in a water/methanol extract of an Early Cretaceous lignite sample (ca. 140 Ma) representing type IV kerogen. No L- or D-aromatic amino acids were detected, reflecting the advanced diagenetic stage and the fossil nature of the sample. The results demonstrate the ability of the liquid extraction by ultrasonication and the versatility of the multiplex inhibitory immunoassays in the SOLID instrument to discriminate between organic matter derived from life and nonlife processes, an essential step toward life detection outside Earth

We study the bias induced by a weak (200 mT) external magnetic field on the preferred handedness of sodium chlorate crystals obtained by slow evaporation at ambient conditions of its saturated saline solution with 20 ppm of added racemic (dl) hydrophobic amino acids. By applying the Fisher test to pairs of experiments with opposing magnetic field orientation we conclude, with a confidence level of 99.7%, that at the water-air interface of this saline solution there is an enantioselective magnetic interaction that acts upon racemic mixtures of hydrophobic chiral amino acids. This interaction has been observed with the three tested racemic hydrophobic amino acids: dl-Phe, dl-Try and dl-Trp, at ambient conditions and in spite of the ubiquitous chiral organic contamination. This enantioselective magnetic dependence is not observed when there is only one handedness of added chiral amino-acid, if the added amino acid is not chiral or if there is no additive. This effect has been confirmed with a double blind test. This novel experimental observation may have implications for our view of plausible initial prebiotic scenarios and of the roles of the geomagnetic field in homochirality in the biosphere.

Hydrogen cyanide (HCN) is a ubiquitous molecule in the Universe. It is a compound that is easily produced in significant yields in prebiotic simulation experiments using a reducing atmosphere. HCN can spontaneously polymerise under a wide set of experimental conditions. It has even been proposed that HCN polymers could be present in objects such as asteroids, moons, planets and, in particular, comets. Moreover, it has been suggested that these polymers could play an important role in the origin of life. In this review, the simple organics and biomonomers that have been detected in HCN polymers, the analytical techniques and procedures that have been used to detect and characterise these molecules and an exhaustive classification of the experimental/environmental conditions that favour the formation of HCN polymers are summarised. Nucleobases, amino acids, carboxylic acids, cofactor derivatives and other compounds have been identified in HCN polymers. The great molecular diversity found in HCN polymers encourages their placement at the central core of a plausible protobiological system.

We have studied the in situ coordination reaction of porphyrin molecules, particularly protoporphyrin IX (H2PPIX), with copper substrate atoms in ultrahigh vacuum conditions with a combination of X-ray photoelectron spectroscopy and scanning tunneling microscopy. We show that these protoporphyrin IX molecules deposited on Cu surfaces, as Cu(110) and Cu(100), form metalloprotoporphyrin IX (CuPPIX) by incorporation of Cu atoms from the surface already at room temperature. We have followed this reaction as a function of temperature and we have determined intermediate situations at lower temperatures where the physisorbed macrocycle rings present a tendency to establish hydrogen bonding between molecules.

The particular mineralogy formed in the acidic conditions of the Río Tinto has proven to be a first-order analogue for the acid-sulfate aqueous environments of Mars. Therefore, studies about the formation and preservation of biosignatures in the Río Tinto will provide insights into equivalent processes on Mars. We characterized the biomolecular patterns recorded in samples of modern and old fluvial sediments along a segment of the river by means of an antibody microarray containing more than 200 antibodies (LDCHIP200, for Life Detector Chip) against whole microorganisms, universal biomolecules, or environmental extracts. Samples containing 0.3–0.5 g of solid material were automatically analyzed in situ by the Signs Of LIfe Detector instrument (SOLID2), and the results were corroborated by extensive analysis in the laboratory. Positive antigen-antibody reactions indicated the presence of microbial strains or high-molecular-weight biopolymers that originated from them. The LDCHIP200 results were quantified and subjected to a multivariate analysis for immunoprofiling. We associated similar immunopatterns, and biomolecular markers, to samples with similar sedimentary age. Phyllosilicate-rich samples from modern fluvial sediments gave strong positive reactions with antibodies against bacteria of the genus Acidithiobacillus and against biochemical extracts from Río Tinto sediments and biofilms. These samples contained high amounts of sugars (mostly polysaccharides) with monosaccharides like glucose, rhamnose, fucose, and so on. By contrast, the older deposits, which are a mix of clastic sands and evaporites, showed only a few positives with LDCHIP200, consistent with lower protein and sugar content. We conclude that LDCHIP200 results can establish a correlation between microenvironments, diagenetic stages, and age with the biomarker profile associated with a sample. Our results would help in the search for putative martian biomarkers in acidic deposits with similar diagen

The present invention relates to a novel method and to a device for obtaining crystals from a substance, comprising: (i) preparing a saturated dissolution of the substance to be crystallized in a suitable solvent in a reaction vessel; (ii) generating an aerosol in the reaction vessel; (iii) crystallizing the substance; and (iv) recovering the crystals at the bottom of the reaction vessel. The method is especially suitable for crystallizing substances which are typically difficult to crystallize and can lead to a chiral amplification result., La presente invención relaciona a un nuevo método y a un dispositivo para obtener los cristales de una sustancia, comprendiendo: (i) preparando una disolución saturada de la sustancia que se cristalizará en un disolvente adecuado en un recipiente de reacción (ii) generar un aerosol en el recipiente de reacción (iii) cristalizar la sustancia y (iv) recuperando los cristales en el fondo del recipiente de reacción. El método es especialmente adecuado para cristalizar las sustancias que el son típicamente difícil cristalizar y el bote conducen a un resultado de la amplificación del quiral.

Certain local atmospheric anomalies, such as the formation of unusually large ice conglomerations (megacryometeors), have been proposed to be a potential natural hazard for people and aviation, as well as geoindicators for fingerprinting larger-scale atmospheric environmental changes. On March 13th 2007, at approximately 10:15 am, an ice chunk weighing about 10 kg fell from the clear-sky and crashed through the roof (around 15 m) of an industrial storage house in Mejorada del Campo, a town located 20 km east from Madrid. The megacryometeor monitoring follow-up and the original investigation presented here includes, for the first time, both logistic and scientific collaboration between the Laboratory of the Environment, Criminalistic Service (SECRIM, the Spanish “Guardia Civil”) and academic and scientific institutions (universities and the Spanish National Research Council). We propose that the management procedure of the incident, along with the detailed scientific research and combination of analytical methodologies in different laboratories, can serve as a protocol model for other similar events

We report the synthesis of purine bases and other heterocycles and the formation of amino acids, hydroxy acids and dihydroxy compounds by the spark activation of an atmosphere of methane, nitrogen and hydrogen, in the presence of an aqueous aerosol. With the aid of the interface air–water, the organic material obtained shows greater amounts and diversity of molecules with biological interest than the products obtained in the absence of an aerosol. Our results support the suggestion that aerosols may have played a significant role in the prebiotic origin of molecular diversity and evolution.

It has been postulated that the oceans on early Earth had a salinity of 1.5 to 2 times the modern value and a pH between 4 and 10. Moreover, the presence of the banded iron formations shows that Fe(+2) was present in significant concentrations in the primitive oceans. Assuming the hypotheses above, in this work we explore the effects of Fe(+2) and other ions in the generation of biomolecules in prebiotic simulation experiments using spark discharges and aqueous aerosols. These aerosols have been prepared using different sources of Fe(+2), such as FeS, FeCl(2) and FeCO(3), and other salts (alkaline and alkaline earth chlorides and sodium bicarbonate at pH = 5.8). In all these experiments, we observed the formation of some amino acids, carboxylic acids and heterocycles, involved in biological processes. An interesting consequence of the presence of soluble Fe(+2) was the formation of Prussian Blue, Fe(4)[Fe(CN)(6)](3), which has been suggested as a possible reservoir of HCN in the initial prebiotic conditions on the Earth.

Ferrocyanide has been proposed as a potential prebiotic reagent by Arrhenius. The complex salt named Prussian Blue, Fe4[Fe(CN)6]3, [ferric hexacyaneferrate (II)], might be an important reservoir of hydrogen cyanide, HCN, in the early Earth. HCN is a major product of spark discharge experiments on various gas mixtures; it is considered the main precursor of amino acids and purine bases under prebiotic conditions. The presence of banded iron formations shows that dissolved iron (ferrous iron) was present in high quantities in the ocean water during Archean epoch. Recently, we observed the formation of Prussian Blue in spark discharge experiments using saline solutions of ferrous chloride, FeCl3. Using Prussian Blue as starting material in ammonium solutions at different values of pH, and carrying out the reactions under middle conditions of temperature and concentration, some organic compounds were formed. We detected urea, imidazole, substituted imidazoles, methyl hydantoines and other heterocycles containing nitrogen and some amino acids by GC-MS of their trimethylsilyl derivatives. These results seem to indicate that Prussian Blue could be a sink of HCN in the early Earth. Subsequent reactions, triggered by pH fluctuations, might lead to organic life precursors.