ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Wearable hydration and pH sensor based on protein film for healthcare monitoring

Chen Hou, Fan Zhang, Caifeng Chen, Yifan Zhang, Ronghui Wu, Liyun Ma, Changjian Lin, Wenxi Guo, and Xiang Yang Liu

Research Institute for Biomimetics and Soft Matter, College of Materials, Shenzhen Research Institute of Xiamen University, Xiamen, China

E-mail: wxguo@xmu.edu.cn

Received: 29 October 2020  Accepted: 24 March 2021

Abstract:

Hydration and pH monitoring provide clinically relevant information of preventative medicine, disease diagnostics, and patient care is of great importance. However, traditional materials have limited in flexible sensors due to the long-term on-skin health monitoring, which requires high flexibility, biocompatibility, biodegradability, comfortableness, and air permeability. In this paper, micro hydration and pH sensors were integrated on a composite silk fibroin (C–SF) film for real-time health monitoring. The excellent biocompatibility and flexibility of the C–SF film allow long-term non-allergenic and comfortable with skin contact. Moreover, the flexible hydration sensors had high selectivity and sensitivity, which was sensitive to hydration change in skin and insensitive to humidity change. Within the range of hydration from 25 to 65%, the change of the capacitance has a certain linear relationship C = 0.0121 M (%) + 2.9477 where, C is the capacitance value of the hydration sensor, M is the hydration of the artificial skin. In addition, pH response in different phosphate buffered saline (PBS) linearly is increased from 4 to 9. The open-circuit voltage (OCV) is decreased from  − 0.023 to  − 0.136 mV. Wearable multifunctional sensors potentially allow ‘fit for purpose’ biomedical applications, such as long-term health monitoring and disease alerts.

Keywords: Hydration sensor; PH sensor; Composite silk fibroin film; Monitoring health

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01627-6

Chemical Papers 75 (9) 4927–4934 (2021)