Novel glucose-responsive of the transparent nanofiber hydrogel patches as a wearable biosensor via electrospinning

Gun Jin Kim,Kyu Oh Kim

doi:10.1038/s41598-020-75906-9

Abstract

Micro- and nanofiber (NF) hydrogels fabricated by electrospinning to typically exhibit outstanding high porosity and specific surface area under hydrated conditions. However, the high crystallinity of NFs limits the achievement of transparency via electrospinning. Transparent poly(vinyl alcohol)/β-cyclodextrin polymer NF hydrogels contacted with reverse iontophoresis electrodes were prepared for the development of a non-invasive continuous monitoring biosensor platform of interstitial fluid glucose levels reaching ~ 1 mM. We designed the PVA/BTCA/β-CD/GOx/AuNPs NF hydrogels, which exhibit flexibility, biocompatibility, excellent absorptivity (DI water: 21.9 ± 1.9, PBS: 41.91 ± 3.4), good mechanical properties (dried: 12.1 MPa, wetted: 5.33 MPa), and high enzyme activity of 76.3%. Owing to the unique features of PVA/β-CD/GOx containing AuNPs NF hydrogels, such as high permeability to bio-substrates and rapid electron transfer, our biosensors demonstrate excellent sensing performance with a wide linear range, high sensitivity(47.2 μA mM−1), low sensing limit (0.01 mM), and rapid response time (< 15 s). The results indicate that the PVA/BTCA/β-CD/GOx/AuNPs NF hydrogel patch sensor can measure the glucose concentration in human serum and holds massive potential for future clinical applications.

Highlights

Micro- and nanofiber (NF) hydrogels fabricated by electrospinning to typically exhibit outstanding high porosity and specific surface area under hydrated conditions
Wearable biosensors are capable of a non-invasive analysis of biomarkers present in the saliva, tear, interstitial fluid (ISF), sweat, and blood
The results presented in this study contribute to both fundamental and clinical research as well as show high potential for continuous and non-invasive glucose monitoring from ISFs

Summary

Introduction

Micro- and nanofiber (NF) hydrogels fabricated by electrospinning to typically exhibit outstanding high porosity and specific surface area under hydrated conditions. Transparent poly(vinyl alcohol)/βcyclodextrin polymer NF hydrogels contacted with reverse iontophoresis electrodes were prepared for the development of a non-invasive continuous monitoring biosensor platform of interstitial fluid glucose levels reaching ~ 1 mM. Wearable biosensors are capable of a non-invasive analysis of biomarkers present in the saliva, tear, interstitial fluid (ISF), sweat, and blood They can detect gas molecules contained in the exhaled breath. The development of a non-invasive biosensor capable of detecting low glucose levels in ISF with a low detection limit, high sensitivity, selectivity, faster response time, and good stability for long-term monitoring is deemed necessary. Preparation of porous hydrogels through the use of metal–organic frameworks[6], gas formation[7], salt leaching[8], and freeze-drying method[9] These studies have reported the limitations of these methods in controlling the pore size distribution. The electrospun nanofibrous membrane owing to their high surface area can effectively immobilize enzymes compared to that of thin films[13]

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Results

Conclusion