Samsung Advanced Institute of Technology

Accurate assessment of dietary macronutrients intake is critical for the effective management of multiple diseases, such as obesity, diabetes, cardiovascular disease, metabolic disease, and cancer. Conventional self-reporting method is burdensome, inaccurate, and often biased. Though blood analysis and breath analysis can provide evidence-based information, they are either invasive or subject to human errors. Here we reported a wearable transdermal volatile biomarkers detection system based on novel colorimetric sensing technology for dietary macronutrients intake assessment. This technique quantifies the emission rates of transdermal volatile biomarkers via a gradient-based colorimetric array sensor (GCAS). The optical system of the GCAS device tracks the localized color development associated with the chemical reaction between the volatile biomarkers and the porous sensing probes, and determines the biomarkers emission rates through image processing algorithms. The localized chemical reaction and the image-based signal processing also make the GCAS capable for multiplexed detection of multiple analytes simultaneously. The acetone sensor was applied for skin acetone test on 5 subjects after different diets, which indicate the acetone will increase after keto diets and decrease to basal level after intake of carb-rich diets. The sensor response correlated well with breath acetone concentration of range between 0 to 40 ppm with linear relationship (sensor response = 0.00112 x breath acetone concentration+0.00176, R² = 0.8168). This method provides a noninvasive, low-cost, and wearable tool for assessing dietary macronutrients intake outside of lab or hospital settings. It could be widely applied in disease management, weight control, and nutrition management.