Aquaphotomics-From Innovative Knowledge to Integrative Platform in Science and Technology

Abstract

Aquaphotomics is a young scientific discipline based on innovative knowledge of water molecular network, which as an intrinsic part of every aqueous system is being shaped by all of its components and the properties of the environment. With a high capacity for hydrogen bonding, water molecules are extremely sensitive to any changes the system undergoes. In highly aqueous systems-especially biological-water is the most abundant molecule. Minute changes in system elements or surroundings affect multitude of water molecules, causing rearrangements of water molecular network. Using light of various frequencies as a probe, the specifics of water structure can be extracted from the water spectrum, indirectly providing information about all the internal and external elements influencing the system. The water spectral pattern hence becomes an integrative descriptor of the system state. Aquaphotomics and the new knowledge of water originated from the field of near infrared spectroscopy. This technique resulted in significant findings about water structure-function relationships in various systems contributing to a better understanding of basic life phenomena. From this foundation, aquaphotomics started integration with other disciplines into systematized science from which a variety of applications ensued. This review will present the basics of this emerging science and its technological potential.

Keywords: aquaphotomics; biodiagnosis; biomeasurements; biomonitoring; light; near infrared spectroscopy; perturbation; water; water-mirror approach.

Figure 1

Water spectrum (double logarithmic plot), based on data from Segelstain [17].

Figure 2

Number of articles published per year mentioning word “aquaphotomics” since 2006. The numbers are obtained using Google Scholar web search engine for articles and patents (excluding citations) containing word “aquaphotomics”.

Figure 3

Spectra of pure water (produced by Milli-Q water purification system (Millipore, Molsheim, France) in the visible-near infrared region (400–2500 nm). Five spectra (miliQ_consNr1, miliQ_consNr2, miliQ_consNr5) presented in the figure were acquired by illuminating the same water sample five times consecutively.

Figure 4

Spectra of pure water subjected to consecutive illuminations (the same spectra presented in Figure 3) in the area of the first overtone of water.

Figure 5

Consecutive illumination of water changes the near infrared spectra. Difference spectra calculated by subtracting the first consecutive spectrum from four subsequently acquired spectra under consecutive illuminations (the same spectra from Figure 3 and Figure 4), show that near infrared light changes the water spectral pattern.

Figure 6

PLSR model for prediction of UV irradiation dose: (A) Y-fit curve showing relationship between actual and predicted values; (B) regression vector of PLSR model showing water absorbance bands affected by UV light perturbation [48].

Figure 7

An example of a collagen peptide and its hydration shell: (a) in conventional science, biomolecules are usually represented only by this main chain on a black background, as if the biomolecular processes are happening in the vacuum; (b–d), a realistic picture, showing water hydration shells as an integral part [57] (Reprinted from Bella J, Brodsky B, Berman HM. Hydration structure of a collagen peptide. Structure 1995; 3:893–906, with permission from Elsevier).

Figure 8

Dynamics of different water species (S_i = water molecules with i hydrogen bonds, S_r = protonated water clusters) during dehydration and rehydration of Haberlea rhodopensis and Deinostigma eberhardtii. Relative absorbance of water species in Haberlea rhodopensis (A) and Deinostigma eberhardtii (B) during desiccation and subsequent rehydration [72].

Figure 9

Water spectral pattern of spent dialysate presented on aquagram can be used as a marker of dialysis efficacy. Instead of measurements of different uremic toxins (of which there are more than 80), aquaphotomics provides measurement of their collective cumulative effect on water matrix of spent dialysate. [67].

Figure 10

Aquagrams of culture media of groups of probiotic, moderate and non-probiotic strains. Average values of normalized absorbance values of the water matrix coordinates for each group are plotted on each wavelength axis [89].