Tuning Nanoscopic Water Layers on Hydrophobic and Hydrophilic Surfaces with Laser Light

Abstract

The evolutional function of ordered interfacial water near solid surfaces was postulated by Szent-Györgyi: "Life actually, may have started with building these water structures." Here we report their tunability with laser light on both hydrophobic and hydrophilic surfaces. On the former, the light caused their depletion--on the latter, an increase in fluidity--as measured by atomic force acoustic microscopy. Interfacial water layers play a key role in cellular recognition. Their tunability promises to revolutionize various fields in biomedical engineering and life sciences.

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“…Collectively these studies imply that so-called "non-bulk" water may "jacket" all biologically-active molecules and membranes, including intracellular organelles, mitochondria, DNA and RNA. This jacketing proposition is in principle consistent with a statement made by Tsai and Hamblin (2017), citing Sommer et al (2008), that "Cellular membranes are characterized by the presence of a thin (nanometer) layer of water that builds up on hydrophobic surfaces. "…”

670 nm Laser Light and EGCG Complementarily Reduce Amyloid-β Aggregates in Human Neuroblastoma Cells: Basis for Treatment of Alzheimer's Disease?

“…14 The function of the intermittent irradiation mode is to facilitate the transport of the active compound into cells via transmembrane convection, a mechanism based on the interaction of 670-nm light with nanoscopic interfacial water layers on surfaces. 15,16 The cause of the convective flow across the plasma membrane is the simultaneous modulation of the density and viscosity of the nanoscopic interfacial water layers prevailing between intracellular surfaces (macromolecules and organelles). The effect is expected to be most pronounced in cells that are rich in mitochondria.…”

From Microtornadoes to Facial Rejuvenation: Implication of Interfacial Water Layers

“…The surfaces employed by us to study interfacial water layers were hydrophobic or hydrophilic. [6][7][8][9] Normally, they preserved their original surface polarities during the period of the measurement, even in water containing nanoparticles. 8 Apparently, their presence had no effect on the prevalent interfacial water structure.…”

“…Earlier we demonstrated that 670 nm laser light, applied in the same intensity range, depleted interfacial water layers in air, 6,7 and transformed their crystalline structure subaquatically. 8 From an analysis of the prevalent molecular situations at the relevant interfaces (loss of one degree of freedom due to unilateral restriction in mobility) we predicted interfacial water densities superior to that of bulk water.…”

“…Experimentally, interfacial water layers have been studied by X-rays and neutron scattering, 1,2 atomic force microscopy (AFM), [3][4][5] near-field scanning optical microscopy (NSOM), 6 atomic force acoustic microscopy (AFAM), 7 drop evaporation experiments, 8 and recently on hydrogen-terminated nanocrystalline diamond. 9 A synoptic analysis of all these perspectives provides an increasingly clear picture of the nature of interfacial water: The central and probably generalizable result seems to be that the structural difference between water layers on a solid surface exposed to air, and water layers that prevail at the interface between the same solid surface and bulk water, is less pronounced than that between water layers on a hydrophobic and a hydrophilic surface, studied under identical conditions.…”