Hybrid Volatolomics and Disease Detection

Abstract

This Review presents a concise, but not exhaustive, didactic overview of some of the main concepts and approaches related to "volatolomics"-an emerging frontier for fast, risk-free, and potentially inexpensive diagnostics. It attempts to review the source and characteristics of volatolomics through the so-called volatile organic compounds (VOCs) emanating from cells and their microenvironment. It also reviews the existence of VOCs in several bodily fluids, including the cellular environment, blood, breath, skin, feces, urine, and saliva. Finally, the usefulness of volatolomics for diagnosis from a single bodily fluid, as well as ways to improve these diagnostic aspects by "hybrid" approaches that combine VOC profiles collected from two or more bodily fluids, will be discussed. The perspectives of this approach in developing the field of diagnostics to a new level are highlighted.

A Compendium of Volatile Organic Compounds (VOCs) Released By Human Cell Lines

“…Breath volatiles mainly would be derived from living cells of the body and eventually also from the presence of infectious agents, while feces will contain a small fraction of cells derived from the gut lining and a substantial fraction of bacteria. A particular focus of VOC research has been on their possible use as bio-markers for various diseases [19-22], most promi-nently cancer [4, 21-33], but also liver [34-37], or renal diseases [38-41]. However, the problem with selection of breath biomarkers for cancer is very complex and advanced quantitative statistical tests need to be applied as those compounds are typically present not only in cancer patients but also in healthy controls, hence the clinical relevance could not be demonstrated for any of the so far reported candidate VOCs.…”

Self-Healable Sensors Based Nanoparticles for Detecting Physiological Markers via Skin and Breath: Toward Disease Prevention via Wearable Devices

“…A promising approach for monitoring the physiological parameters of healthy people is based on the continuous (or frequent) detection of volatile organic compounds (VOCs) [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] and/or pressure pulses that are derived from human breath/skin, along with monitoring of heart-beat and breath rate, inter alia. 21,22 This approach has the potential to be painless, easy-to-perform, inexpensive and give results that can be available immediately for therapeutic assessment/diagnosis.…”

“…3,7 To make this vision a reality a platform of smart flexible sensors has to be developed and implemented. 3 Among many kinds of sensing schemes, [25][26][27][28][29][30] flexible chemical sensor matrices based on molecularly-modified gold nanoparticles (GNPs) 14,[31][32][33][34] are likely to become realistic wearable devices for health monitoring of VOCs from the skin and breath; they are printable, small, easy-to-use, require only low voltage for operation, and are inexpensive.…”

“…3,7 To make this vision a reality a platform of smart flexible sensors has to be developed and implemented. 3 Among many kinds of sensing schemes, [25][26][27][28][29][30] flexible chemical sensor matrices based on molecularly-modified gold nanoparticles (GNPs) 14,[31][32][33][34] are likely to become realistic wearable devices for health monitoring of VOCs from the skin and breath; they are printable, small, easy-to-use, require only low voltage for operation, and are inexpensive. 14,[31][32][33][34] Sensors based on GNPs also offer the advantages of ppb detection limits for the VOCs of interest, a wide dynamic range, room temperature operation, tolerance of background molecules (particularly variations in humidity levels since exhaled breath is fully humidified), reasonable dimensions, and low cost inter alia.…”

Artificially intelligent nanoarrays for disease detection via volatolomics

“…chemical processes involving profiles of highly volatile organic compounds (VOCs) which are by-products of metabolic and pathological processes and are emitted from various body fluids including breath, skin, urine, blood, and others. (3)(4)(5) According to this approach, each disease has its own unique VOC pattern, and therefore, will not be screened by other diseases. (6) Powerful tools, such as spectrometry and spectroscopy methods, have proven to be effective for identification and quantification of human volatolomics.…”