Dr. Le YANG
Head of Department, Principal Scientist, Institute of Materials Research and Engineering, A*STAR
Dr Le Yang received her PhD from the University of Cambridge, where she and her colleagues discovered a new emission mechanism in a class of then-new materials, leading to a breakthrough and record-efficiency organic LEDs, useful for next-generation display technology. Le is now working in IMRE, on luminescent materials, optoelectronics and biosensors, leading the “PROFESS” Group (Printed Organic Flexible Electronics & Sensors). She is also the Head of Department (Sensors & Flexible Electronics), and currently Adjunct Asst Prof in National University of Singapore. Her notable work has been published in Science, Nature Materials, Nature Communications, Joule, etc; and her team has produced numerous IPs/patents. Le is active in the ecosystem, eg being Associate Editor of Materials Today Chemistry, Joint-Secretary executive committee of the Materials Research Society-Singapore, chairing several conferences and leading outreach activities. Lastly, Le is a recipient of many research awards, including the L’OReal-UNESCO For Women in Science Singapore (2023), MIT Tech Review Innovators Under 35 Asia Pacific (2023), and the National Research Foundation Fellowship (2023).
Presentation Title:
Wearable On-Skin Chemo-sensors
Abstract
In an increasingly health-aware population and a move towards remote diagnostics, remote healthcare monitoring and cloud-based med-tech, we tap on the ubiquitous and unlimited reservoir of on-skin biomarkers, including sweat metabolites, in developing a wearable, non-invasive, continuous and real-time sensor – a printed, multiplexed biosensor. Such a device can be colorimetric or electrochemical in its sensing mechanism. Our integrated devices are designed and developed with scalability and translation in mind – ensuring printability (for scalable manufacturing), ease of fabrication routes, and solid-state and miniaturised prototype. In particular, we emphasize on wearable chemo-sensors that allow for non-invasive continuous monitoring of chemical markers from our body (skin) without the presence of bodily fluid, enabling a wide range of use-cases and accessible populations. In such devices, enabling chemo-sensing without a fluidic environment [1], and addressing the need of a stable, sensitive and selective enzyme complex for the sensor [2], are two key challenges.
Firstly, we highlight a holistic approach in developing a printable, non-invasive, real-time and continuous electrochemical sensor for sweat-based and ‘sweat-free’ based on-skin chemosensing, demonstrated by the detection of both a water-soluble analyte (lactate) and a water-insoluble analyte (cholesterol). We showcase benchtop to on-body analytics, including correlation with serum readings. [1]
Next, we highlight the importance of enzymes in such enzymes-based biosensors (enzymatic reactions to detect target analytes), where their intrinsic instability poses a bottleneck in practical long-term use. Previous methods at enhancing enzyme stability had always been met with a trade-off in sensitivity, selectivity or performance/efficacy. Herein, we showcase a novel materials-based approach, a one-pot synthesis of co-encapsulating enzymes and carbon-dots in a metal-organic framework, overcoming the aforementioned compromise. We achieve an electrochemical highly-stable and highly-sensitive device, and demonstrate it as a touch-based sweat sensor. [2]
Lastly, for wearable sweat-based sensors, we have developed both electrochemical and colorimetric based technologies for holistic monitoring. This includes a fully-printed paper-based colorimetric patch, printed from our development of a ceramic-based ink along with nanoparticle-functionalisation, for multi-metabolite and sweat rate monitoring.[3] We also have a integrated electrochemical device named ‘WISH’ (Wearable Integrated Sweat-sensors for Health) that focus on real-time and continuous biochemical concentrations in sweat.[4-6]
[1] RT Arwani, SCL Tan, WP Goh, CY Jiang, XT Zheng, Y Yu, L Yang* and YX Liu* et al, “tretchable ionic-electronic bilayer hydrogel electronics enabled in situ detection of solid-state epidermal biomarkers.” Nature Materials (2024) (Accepted).
[2] XT Zheng*, MWN Leoi, Y Yu, SCL Tan, N Nadzri, WP Goh, C Jiang, XP Ni, P Wang, M Zhao, L Yang*, “Co‐Encapsulating Enzymes and Carbon Dots in Metal–Organic Frameworks for Highly Stable and Sensitive Touch‐Based Sweat Sensors” Advanced Functional Materials, 2310121 (2023).
[3] XT Zheng, WP Goh, Y Yu, L Sutarlie, DY Chen, SCL Tan, C Jiang, M Zhao, T Ba, H Li, X Su, L Yang*, “Skin‐Attachable Ink‐Dispenser‐Printed Paper Fluidic Sensor Patch for Colorimetric Sweat Analysis” Advanced Healthcare Materials, 2302173 (2023).
[4] A graphite-based paste/ink for electrochemical sensors, WP Goh, CY Jiang, Y Yu, XT Zheng, YX Liu, LYang, PCT/SG2022/050407, Singapore (PCT filed), 2022.
[5] A kirigami paper fluidic channel for sweat sensors, CY Jiang, WP Goh, XT Zheng, Y Yu, YX Liu, L Yang,SG-10202113328Q, Singapore (PCT filed), 2023.
[6] Y Yu, L Yang et al, Materials Today Advances, 14, 100238 (2022).