An official website of the United States government
Wearable sweat biosensors offer compelling opportunities for improved personal health monitoring and non-invasive measurements of key biomarkers. Inexpensive device fabrication methods are necessary for scalable manufacturing of portable, disposable, and flexible sweat sensors. Furthermore, real-time sweat assessment must be analyzed to validate measurement reliability at various sweating rates. Here, we demonstrate a “smart bandage” microfluidic platform for cortisol detection and continuous glucose monitoring integrated with a synthetic skin. The low-cost, laser-cut microfluidic device is composed of an adhesive-based microchannel and solution-processed electrochemical sensors fabricated from inkjet-printed graphene and silver solutions. An antibody-derived cortisol sensor achieved a limit of detection of 10 pM and included a low-voltage electrowetting valve, validating the microfluidic sensor design under typical physiological conditions. To understand effects of perspiration rate on sensor performance, a synthetic skin was developed using soft lithography to mimic human sweat pores and sweating rates. The enzymatic glucose sensor exhibited a range of 0.2 to 1.0 mM, a limit of detection of 10 μM, and reproducible response curves at flow rates of 2.0 μL min −1 and higher when integrated with the synthetic skin, validating its relevance for human health monitoring. These results demonstrate the potential of using printed microfluidic sweat sensors as a low-cost, real-time, multi-diagnostic device for human health monitoring.
more »
« less
A Highly Sensitive and Long‐Term Stable Wearable Patch for Continuous Analysis of Biomarkers in Sweat
Abstract Although increasing efforts have been devoted to the development of non‐invasive wearable electrochemical sweat sensors for monitoring physiological and metabolic information, most of them still suffer from poor stability and specificity over time and fluctuating temperatures. This study reports the design and fabrication of a long‐term stable and highly sensitive flexible electrochemical sensor based on nanocomposite‐modified porous graphene by facile laser treatment for detecting biomarkers such as glucose in sweat. The laser‐reduced and patterned stable conductive nanocomposite on the porous graphene electrode provides the resulting glucose sensor with an excellent sensitivity of 1317.69 µA mm−1cm−2and an ultra‐low limit of detection of 0.079 µm. The sensor can also detect pH and exhibit extraordinary stability to maintain more than 91% sensitivity over 21 days in ambient conditions. Taken together with a temperature sensor based on the same material system, the dual glucose and pH sensor integrated with a flexible microfluidic sweat sampling network further results in accurate continuous on‐body glucose detection calibrated by the simultaneously measured pH and temperature. The low‐cost, highly sensitive, and long‐term stable platform could facilitate the early identification and continuous monitoring of different biomarkers for non‐invasive disease diagnosis and treatment evaluation.
more »
« less
- PAR ID:
- 10462727
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 33
- Issue:
- 52
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Wearable health monitoring has garnered considerable interest from the healthcare industry as an evolutionary alternative to standard practices with the ability to provide rapid, off‐site diagnosis and patient‐monitoring. In particular, sweat‐based wearable biosensors offer a noninvasive route to continuously monitor a variety of biomarkers for a range of physiological conditions. Both the accessibility and wealth of information of sweat make it an ideal target for noninvasive devices that can aid in early diagnosis of disease or to monitor athletic performance. Here, the integration of ammonium (NH4+) and calcium (Ca2+) ion‐selective membranes with a poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate)‐based (PEDOT:PSS) organic electrochemical transistor (OECT) for multiplexed sensing of NH4+and Ca2+in sweat with high sensitivity and selectivity is reported for the first time. The presented wearable sweat sensor is designed by combining a flexible and stretchable styrene‐ethylene‐butene‐styrene substrate with a laser‐patterned microcapillary channel array for direct sweat acquisition and delivery to the ion‐selective OECT. The resulting dermal sensor exhibits a wide working range between 0.01 × 10−3and 100 × 10−3m, well within the physiological levels of NH4+and Ca2+in sweat. The integrated devices are successfully implemented with both ex situ measurements and on human subjects with real‐time analysis using a wearable sensor assembly.more » « less
-
Abstract Microfluidic‐based wearable electrochemical sensors represent a transformative approach to non‐invasive, real‐time health monitoring through continuous biochemical analysis of body fluids such as sweat, saliva, and interstitial fluid. These systems offer significant potential for personalized healthcare and disease management by enabling real‐time detection of key biomarkers. However, challenges remain in optimizing microfluidic channel design, ensuring consistent biofluid collection, balancing high‐resolution fabrication with scalability, integrating flexible biocompatible materials, and establishing standardized validation protocols. This review explores advancements in microfluidic design, fabrication techniques, and integrated electrochemical sensors that have improved sensitivity, selectivity, and durability. Conventional photolithography, 3D printing, and laser‐based fabrication methods are compared, highlighting their mechanisms, advantages, and trade‐offs in microfluidic channel production. The application section summarizes strategies to overcome variability in biofluid composition, sensor drift, and user adaptability through innovative solutions such as hybrid material integration, self‐powered systems, and AI‐assisted data analysis. By analyzing recent breakthroughs, this paper outlines critical pathways for expanding wearable sensor technologies and achieving seamless operation in diverse real‐world settings, paving the way for a new era of digital health.more » « less
-
Abstract More than half of all Americans suffer from chronic diseases, the leading causes of death and disability. However, prompt treatment of chronic diseases can lead to better patient outcomes and a reduced burden on the healthcare system. This highlights the urgent need for electrochemical (EC) sensors that provide non‐invasive, real‐time monitoring of disease‐indicating biomarkers. Due to their high sensitivity, high selectivity, and cost‐effectiveness, EC biosensors have recently shown tremendous promise for individualized health monitoring. This review explains the working principles of EC biosensors. It summarizes the recent advances and improvements of EC biosensors for detecting biomarkers in different biofluids, including tears, saliva, breath, urine, and sweat. Through a comprehensive overview of EC biosensor technologies, this article is expected to aid the development of flexible and wearable EC biosensing systems that have the potential to provide continuous, long‐term health monitoring for both clinical and at‐home use.more » « less
-
Uniform and porous CoNi 2 Se 4 was successfully synthesized by electrodeposition onto a composite electrode comprising reduced graphene oxide (rGO) anchored on a Ni foam substrate (prepared hydrothermally). This CoNi 2 Se 4 –rGO@NF composite electrode has been employed as an electrocatalyst for the direct oxidation of glucose, thereby acting as a high-performance non-enzymatic glucose sensor. Direct electrochemical measurement with the as-prepared electrode in 0.1 M NaOH revealed that the CoNi 2 Se 4 –rGO nanocomposite has excellent electrocatalytic activity towards glucose oxidation in an alkaline medium with a sensitivity of 18.89 mA mM −1 cm −2 and a wide linear response from 1 μM to 4.0 mM at a low applied potential of +0.35 V vs. Ag|AgCl. This study also highlights the effect of decreasing the anion electronegativity on enhancing the electrocatalytic efficiency by lowering the potential needed for glucose oxidation. The catalyst composite also exhibits high selectivity towards glucose oxidation in the presence of several interferents normally found in physiological blood samples. A low glucose detection limit of 0.65 μM and long-term stability along with a short response time of approximately 4 seconds highlights the promising performance of the CoNi 2 Se 4 –rGO@NF electrode for non-enzymatic glucose sensing with high precision and reliability.more » « less
