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Currently available point‐of‐care systems for body fluid collection exhibit poor integration with sensors. Herein, the design of a disposable device for interstitial fluid (ISF) extraction as well as glucose, lactate, and potassium ion (K+) monitoring is reported on. It is minimally invasive and appropriate for single use, minimizing the risk of infection to the user. This microscale device contains a 3D‐printed cap‐like structure with a four‐by‐four microneedle (MN) array, bioreceptor‐modified carbon fiber (CF)‐sensing surface, and negative pressure convection technology. These features are incorporated within a compact, self‐contained, and manually operated microscale device, which is capable of withdrawing ≈3.0 μL of ISF from the skin. MN arrays applied with an upward driving force may increase the ISF flow rate. Moreover, functionalized CF working electrodes (WE1, WE2, WE3) are shown to selectively detect lactate, glucose, and K+with high sensitivities of 0.258, 0.549, and 0.657 μA μm−1 cm−2and low detection limits of 0.01, 0.080, 0.05 μm, respectively. Ex vivo testing on porcine skin is used to detect the ISF levels of the biomarkers. The microscale device can be a replacement for current point‐of‐care diagnostic approaches.
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Asymmetric Interdigitated Electrodes for Amperometric Detection of Soluble Products
A new electroanalytical design based on asymmetric interdigitated arrays (IDA) is presented and the effects of asymmetry on the device performance are characterized electrochemically. Varying the collector and generator band widths independently of each other tunes the collection efficiency and redox cycling-induced feedback. These arrays are able to provide low feedback (<10%) while maintaining moderate collection efficiency (25%–40%). Behavior is evaluated experimentally and using a numerical model. The application of the device to detect soluble electrolyte degradation products in nonaqueous lithium-ion and sodium-ion battery electrolytes is demonstrated.
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- Award ID(s):
- 1751553
- PAR ID:
- 10362300
- Publisher / Repository:
- The Electrochemical Society
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- Volume:
- 168
- Issue:
- 5
- ISSN:
- 0013-4651
- Page Range / eLocation ID:
- Article No. 057519
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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