Human skin emits light (albeit the glow is extremely weak) and a wide variety of small molecules that may be sometimes "sniffed" by dogs or even other humans. These chemicals tell a story about our health and wellness, things we eat and drink, touch and breathe. Mosquitoes use such emissions to assess our "attractiveness" from indicators such as Indoles (unpleasantly smelling but healthy "inner soil" biomarker) or carbon dioxide (amount of which correlates with the size of the person producing it) in the air.
Sampling air for health indicators is much less invasive than drawing blood and could be an invaluable diagnostic tool. Many applications of gas sensors have been proposed over decades ranging from sweat patches to sensorized garments. Where are we now? What is the 2016 state of the art?
Can we recognize if people around us are stressed, anxious or fearful without observing their facial expressions, body language and actions or hearing their voice and messages? What about our own stress - assuming we don't rely on heart rate, blood pressure, dry throat, sweating, drops or surges in energy? Yes, we can - by using our nose - as humans, too, recognize and transmit their emotions through chemical senses ...
The $10 million Qualcomm Tricorder X Prize and $2.25 million Nokia Sensing Challenges are trying to identify the best portable technologies for diagnosing disease - as easily as Dr. McCoy's tricorder of the 23rd Century could. What scientific knowledge could help us to develop it in this age? Detecting metabolites, sensing DNA, imaging the nanoworld of the human body or interaction between matter and energy?,,,
Despite active foodstagramming and foodteresting, and eagerness to show pictures of meals and diet reports to friends on social media, we don't really want others to know everything we eat. But they might know anyway.
Why worry about NSA, when Google, Facebook, Amazon and many others know what we might be eating. Cameras record our ways to groceries and restaurants, credit cards record our purchases, food chains know our weaknesses, clothes shops know how, as a result, our pant sizes change over time. One day phones will know what we ate too. As both short- and long-term diets change our breath-prints - creating signature metabolites in exhaled breath.
A recent Dutch study actually looked at what gluten-free eating does to our breath. Just 4 week of dieting lead to remarkable - though reversible - differences. (As detected in 20 healthy individuals by gas chromatography coupled with mass spectrometry (TD-GC-tof-MS) in combination with chemometric analysis ). A set of twelve volatile compounds that distinguish gluten-free eaters along with information from Aurametrix knowledgebase is listed in the table below.
All you need is love. Or failing that chocolate. And not only because dark chocolate could lower the risk of heart disease, blood pressure and sugar levels. As Dr. Schieberle's team recently discovered that heart could sense and enjoy the sweet smell of chocolate too. When they put small odor-emitting molecules from chocolate on one side of a dish, cells actually moved towards the aroma...