Soft, wearable, microfluidic system for fluorometric analysis of loss of amino acids through eccrine sweat
Data files
Feb 21, 2025 version files 36.39 KB
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Data_All_rev2.xlsx
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README.md
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Abstract
Amino acids are essential for protein synthesis and metabolic processes in support of homeostatic balance and healthy body functions. This study quantitatively investigates eccrine sweat as a significant channel for loss of amino acids during exercise, to improve an understanding of amino acid turnover and to provide feedback to users on the need for supplement intake. The measurement platform consists of a soft, skin-interfaced microfluidic system for real-time analysis of amino acid content in eccrine sweat. This system relies on integrated fluorometric assays and smartphone-based imaging techniques for quantitative analysis, as a simple, cost-effective approach that does not require electrochemical sensors, electronics or batteries. Human subject studies reveal substantial amino acid losses in sweat from working muscle regions during prolonged physical activities, thereby motivating the need for dietary supplementation. The findings suggest potential applications in healthcare, particularly in athletic and clinical settings, where maintaining amino acid balance is critical for ensuring proper homeostasis.
Description of the data and file structure
Data is structured as the title of the plot, headings including units, and data. Detailed descriptions for abbreviations and units can be found in the manuscript.
Data are organized based on the figure they appear in, in the manuscript: Soft, wearable, microfluidic system for fluorometric analysis of loss of amino acids through eccrine sweat
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Fig.2: Fluorometric analysis of amino acid concentrations in sweat based on enzymatic assays. Fluorescence images and standard curves for total amino acid, alanine, and lysine show fluorescence as a function of concentration. Fluorometric results and those obtained by NMR for total amino acid, alanine, and lysine.
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Fig.3d-f: Time-dynamic analysis of total amino acid, alanine, and lysine in sweat before, during, and after exercise.
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Fig.3g-i: Concentrations of total amino acid, alanine, and lysine in sweat for male and female subjects after exercise from non-working regions and working regions.
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Fig.3j: Concentration of L-amino acid in sweat after exercise and warm water shower from five regions of the body.
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Fig.4c: Correlation of total amino acid loss and total sweat loss after exercise from working and non-working regions.
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Fig.4d-e: Estimated whole-body amino acid loss from exercise and a warm water shower.
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Fig.4f-h: Sweat amino acid levels from a working regions and non-working region during two consecutive exercise sessions comparing the same to recovery methods mentioned previously, for total amino acid, alanine, and lysine.
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Fig.S1: PDMS absorption tests. Analysis of sweat samples before and after transport through PDMS microfluidic channels for total amino acid, alanine, and lysine.
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Fig.S6: Fluorometric results from each enzymatic assay targeting total amino acid, alanine, and lysine, when exposed to potential interferents (10 mM urea, 10mM lactate, 0.5 mM Ca2+, 0.5 mM Mg2+, 10 mM uric acid, and 10 mM glucose) and target amino acids (10 mM total amino acid, 2 mM alanine, and 2 mM lysine).
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Fig.S7: Cross-reactivity between amino acids. Fluorometric results from each enzymatic assay targeting total amino acid, alanine, and lysine, when exposed to various amino acids (1 mM histidine, 1 mM serine, 1 mM ornithine, 1 mM glycine, 1 mM lysine, 1 mM alanine, 0.5 mM leucine, 0.5 mM valine, 0.5 mM glutamic acid, and 0.5 mM aspartic acid).
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Fig.S8: Fluorometric results for the enzymatic assays as a function of reaction time for total amino acid, alanine, and lysine.
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Fig.S9: Fluorometric results for the enzymatic assays at various pH for total amino acid, alanine, and lysine.
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Fig.S10: Temperature dependency of enzymatic assays. Fluorometric results from enzymatic assays for total amino acid, alanine, and lysine of various concentrations and temperatures (28-50 °C). Fluorometric results for 20 mM total amino acid, 2 mM alanine, and 1 mM lysine at various temperatures (28-50 °C).
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Fig.S11: Skin temperature measured pre-exercise, during a 60 min exercise on stationary bike, and post-exercise recovery
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Fig.S12: Fluorometric results for the enzymatic assays as a function of storage time at temperatures 25 °C and -18 °C for total amino acid, alanine, and lysine.
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Fig.S13: Correlation between amino acid concentrations from blood and sweat. Analysis of blood and sweat samples taken during rest, after 30 min exercise on a stationary bike, and comparison results for total amino acid, alanine, and lysine.
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Fig.S14: Time-dynamic analysis of total amino acid in sweat induced by warm water shower and iontophoresis from the thigh and forearm.
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Fig.S17: Whole body sweat loss estimates for exercise and warm water shower.
Sharing/Access information
All data presented in the manuscript can be found in the dataset, with the exception of human subject data which are not publicly available to protect the identity of participants according to the Northwestern University Institutional Review Board (IRB).
Code/Software
Calibration of the fluorometric system was based on fluorescence measured by the Azure SapphireTM Biomolecular Imager and NMR measured by the X500 Bruker Avance III HD system.
Data analysis were performed using ImageJ 1.54d, MATLAB 2024, and Origin 2019.