Continuous monitoring of systemic inflammation through TSLP and Interleukin-13 using the sweat-based AWARE sensor

Chronic inflammatory conditions are mediated by complex cytokine networks that remain challenging to monitor using conventional methods, which are invasive, time-consuming, and limited to single-point measurements. Continuous and non-invasive detection of the inflammatory mediators can provide earlier insights into the disease and the therapeutics. Here, we report a sweat-based non-invasive biosensor for sensitive and selective detection of thymic stromal lymphopoietin (TSLP) and interleukin-13 (IL-13) using electrochemical impedance spectroscopy (EIS). The sensor platform, functionalized with monoclonal antibodies via DTSSP cross-linking, demonstrated stable immobilization as validated by FTIR, cyclic voltammetry, and zeta potential analysis. To confirm the biological presence of these cytokines in inflammatory human sweat, orthogonal MALDI-TOF MS and LC-MS analyses were performed, detecting intact TSLP and IL-13 masses, as well as their characteristic fragment-ion fingerprints. The AWARE sensor has achieved an ultra-low limit of detection of 0.076 pg/mL for TSLP and 0.018 pg/mL for IL-13 with recovery values within clinical standards and minimal interference from sweat constituents. The spiked absolute sample values in human sweat were strongly correlated with the values from endogenous human saliva samples. Experiments simulating real-time monitoring reveal the distinct temporal dynamics of TSLP and IL-13, as well as their relationship. This study has established a sweat-based, non-invasive biosensor, advancing the development of sensors for real-time inflammation tracking. • A non-invasive sweat-based biosensor was developed for ultra-sensitive detection of TSLP and IL-13 using impedance-based electrochemical sensing. • DTSSP-mediated antibody immobilization was validated through multimodal characterization (FTIR, CV, zeta potential), confirming stable and specific surface functionalization. • Endogenous TSLP and IL-13 in human sweat were confirmed using orthogonal MALDI-TOF MS and LC-MS fragment ion analysis, validating sweat as a reliable analytical matrix. • The AWARE platform achieved exceptionally low detection limits (TSLP: 0.076 pg/mL; IL-13: 0.018 pg/mL) with high selectivity, accurate spike-and-recovery performance, and minimal cross-reactivity. • Real-time on-body mimicking experiments captured the temporal hierarchy of TSLP and IL-13 dynamics, demonstrating the potential for continuous monitoring of systemic inflammation.