Hydrogen sulfide (H2S) is a gaseous inflammatory mediator and important signaling molecule for maintaining gastrointestinal (GI) homeostasis. Excess intraluminal H2S in the GI tract has been implicated in inflammatory bowel disease and neurodegenerative disorders; however, the role of H2S in disease pathogenesis and progression is unclear. Herein, an electrochemical gas‐sensing ingestible capsule is developed to enable real‐time, wireless amperometric measurement of H2S in GI conditions. A gold (Au) three‐electrode sensor is modified with a Nafion solid‐polymer electrolyte (Nafion‐Au) to enhance selectivity toward H2S in humid environments. The Nafion‐Au sensor‐integrated capsule shows a linear current response in H2S concentration ranging from 0.21 to 4.5 ppm (
The concentration of dopamine (DA) and tyrosine (Tyr) reflects the condition of patients with Parkinson's disease, whereas moderate paracetamol (PA) can help relieve their pain. Therefore, real‐time measurements of these bioanalytes have important clinical implications for patients with Parkinson's disease. However, previous sensors suffer from either limited sensitivity or complex fabrication and integration processes. This work introduces a simple and cost‐effective method to prepare high‐quality, flexible titanium dioxide (TiO2) thin films with highly reactive (001)‐facets. The as‐fabricated TiO2film supported by a carbon cloth electrode (i.e., TiO2–CC) allows excellent electrochemical specificity and sensitivity to DA (1.390 µA µM−1 cm−2), Tyr (0.126 µA µM−1 cm−2), and PA (0.0841 µA µM−1 cm−2). More importantly, accurate DA concentration in varied pH conditions can be obtained by decoupling them within a single differential pulse voltammetry measurement without additional sensing units. The TiO2–CC electrochemical sensor can be integrated into a smart diaper to detect the trace amount of DA or an integrated skin‐interfaced patch with microfluidic sampling and wireless transmission units for real‐time detection of the sweat Try and PA concentration. The wearable sensor based on TiO2–CC prepared by facile manufacturing methods holds great potential in the daily health monitoring and care of patients with neurological disorders.
more » « less- NSF-PAR ID:
- 10489891
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract R 2= 0.954) with a normalized sensitivity of 12.4% ppm−1when evaluated in a benchtop setting. The sensor proves highly selective toward H2S in the presence of known interferent gases, such as hydrogen (H2), with a selectivity ratio of H2S:H2= 1340, as well as toward methane (CH4) and carbon dioxide (CO2). The packaged capsule demonstrates reliable wireless communication through abdominal tissue analogues, comparable to GI dielectric properties. Also, an assessment of sensor drift and threshold‐based notification is investigated, showing potential for in vivo application. Thus, the developed H2S capsule platform provides an analytical tool to uncover the complex biology‐modulating effects of intraluminal H2S. -
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