Chiral micron-sized H2O aggregates in water: Circular dichroism of supramolecular H2O architectures created by perturbing pure water
Vittorio Eliaa,2, Tamar A. Yinnonb, Rosario Olivaa, Elena Napolia, Roberto Germanoc, Fabrizio Bobbad, Angela Amoresanoa
aDepartment of Chemical Sciences, University ‘‘Federico II’’ Complesso Universitario di Monte. S.Angelo, Via Cintia, I-80126 Naples, Italy.
bK. Kalia, D.N. Kikar Jordan, 90666, Israel.
cPROMETE Srl, CNR Spin off, via Buongiovanni, 49 I-80046 San Giorgio a Cremano (Naples), Italy.
dPhysics Department “E. R. Caianiello”, University of Salerno, 84084 Fisciano (SA), Italy.
1 Author contributions: V.E. conceived and managed the research. R.G. assisted in aforementioned. E.N. prepared the perturbed water samples. R.O. measured the Circular dichroism and Fluorescence spectra. F.B., A.A. and E.N., respectively, carried out the Atomic force microscopy, MALDI-TOF/MS and GC/MS, electric conductivity and pH measurements. T.A.Y. contributed to the theoretical aspects of the research and wrote the manuscript. All authors discussed the results and commented on the manuscript.
2To whom correspondence should be addressed: Vittorio Elia, Dipartimento di Scienze Chimiche Università “Federico II” Napoli, Via Cintia 32, Napoli I-80126, Italy, Tel.+393490843931,E-mail: eliavit@unina.it
3The authors declare no conflict of interests
Keywords: Water; chiral; supramolecular aggregates; structured water; perturbed water
Received June 6, 2016; Revised July 15, 2016; Accepted July 17, 2016; Published: March 2, 2017; Available online: March 3, 2017
Abstract
Creating chiral water aggregates in liquid water challenges scientists. Such aggregates are expected to be significant for many technologies (e.g., chiral sensing or genesis), as well as for the decades-long search for the origins of the pervasiveness of chirality in nature and biohomochirality. Water molecules (H2O) are achiral. The possibility of H2O forming chiral aggregates in liquid water has recently been predicted by computer simulations. Lately, we demonstrated that micron-sized supramolecular H2O aggregates are producible by perturbing pure water, i.e., immersing a hydrophilic membrane in Milli-Q water, stirring the liquid, removing and drying the membrane, and then repeating these steps. In this paper, we report the first experimental evidence that these H2O aggregates are chiral. Circular dichroism spectra of the liquid remaining after removal of the membrane signify an excess of one enantiomer or homochirality. The spectra resemble those of β-sheet ordered biomolecules. Lyophilizing the perturbed water produces a ponderal solid residue. To ensure that impurities (molecules released by the membrane, organic- or bio-contaminants) do not underlie the aforementioned phenomena, we employed state-of-the-art analytic techniques (Matrix-Assisted Laser Desorption/Ionization Time Of Flight and Gas Chromatography both coupled to Mass Spectroscopy, and Ion Chromatography). The perturbed water only contains 10-6 M Fluorine and Sulfate ions released by the membrane and minuscule amounts of contaminants. Our finding that chiral H2O aggregates may form when water flows adjacent to a hydrophilic membrane conceivably may elucidate mirror-symmetry breaking in abiogenesis.