Noninvasive Diabetes Monitoring through Continuous Analysis of Sweat Using Flow-Through Glucose Biosensor

Abstract

We propose monitoring of diabetes through continuous analysis of undiluted sweat immediately after its excretion using a flow-through glucose biosensor. The used biosensors are based on Prussian Blue and glucose oxidase immobilized in perfluorosulfonated ionomer or gel of alkoxysilane; the resulting sensitivity with the latter reaches in batch mode 0.23 A M–1 cm–2, and the calibration range is from 1 μM to 1 mM (flow-through mode). On the basis of the glucose tolerance test known to be a clinically relevant procedure to mimic hyperglycemia, a positive correlation between the rates of glucose concentration increase in blood and in noninvasively collected sweat has been observed (r = 0.75). The observed correlation between sweat and blood considering low-molecular weight metabolites is even better than that observed previously between capillary and vein blood, confirming diagnostic value of sweat for diabetes monitoring. The dynamics of sweat glucose concentration, recorded by means of the proposed biosensor, is in a good accordance with the dynamics of blood glucose content without any time delay, thus offering a prospect for noninvasive monitoring of diabetes.

Flexible Electrochemical Bioelectronics: The Rise of In Situ Bioanalysis

“…c) The relation between iontophoretic sweat and blood glucose levels in healthy subjects (sweat measurements were obtained from glucose sensor). Reproduced with permission . Copyright 2019, American Chemical Society.…”

Relationship Between Sweat and Blood Lactate Levels During Exhaustive Physical Exercise

“…The sweating stimulation through electrophoresis of pilocarpine has been chosen because, first, it does not change the sweat lactate content during the exercise and, second, after such activation lactate concentration in sweat is independent of the rate of sweating . Moreover, using continuous diabetes monitor reported in, we have shown that after pilocarpine activation the rate of sweating retains at a constant level within 30 minutes (Figure S1, Supporting Information), which is enough for the exhaustive incremental exercise.…”

“…Concerning suitability of the above correlation (r>0.8, Figure ) for diagnostics, we note that despite blood being considered as a biological liquid with undoubted diagnostic potential, the lactate content in different vessel systems varies significantly. As we have reported recently, variation rates of lactate concentration upon exhaustive physical exercise for vein and capillary blood display similar Pearson correlation coefficient (0.8), but the regression line passes far from the origin. Hence, the observed correlation between the variation rates of lactate concentration in sweat (thigh, working muscle area) and blood (Figure ) is sufficient for diagnostics.…”

Printed Organic Transistor-based Biosensors for Non-invasive Sweat Analysis

“…Such devices adopt both amperometric and potentiometric measurement systems-for lactate and glucose detection and for electrolyte detection, respectively. Since then, development of various types of totally integrated wearable sweat sensors have progressed to take the form of tattoo films, [86][87][88][89][90] wrist bands, [91][92][93] eye glasses, 94 head bands, 95 underwear, [96][97][98] and socks. 99 Although these sensors can detect analytes in sweat when the sensing elements are exposed to sweat, the detected sweat components are left in the same area and their concentration might increase as more sweat is secreted.…”