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Updated: Nov 16, 2025
Bridging the Bio-Electronic Interface with Biofabrication
Published on: June 6, 2012
Precise positioning of enzymes within hierarchical polymer nanostructures for switchable bioelectrocatalysis
Fengjin Qu1, Xiaoyan Ma2, Julien E Gautrot3
1Center for Regenerative and Reconstructive Medicine, Med-X Institute, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China; Department of Applied Chemistry, School of Natural and Applied Sciences, Northwestern Polytechnical University, Xi'an, 710072, China; Institute of Bioengineering, Queen Mary University of London, Mile End Road, London, E1 4NS, UK; School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
This study developed switchable bioelectrocatalytic sensors using polymer brushes for precise enzyme positioning. These responsive biosensors offer a low detection limit and broad sensing range, ideal for biomonitoring.
Area of Science:
- Biotechnology
- Materials Science
- Electrochemistry
Background:
- Reversible bioelectrocatalytic sensors are crucial for advanced biomonitoring and biosensor protection.
- Challenges include maintaining biocatalytic function through environmental cycles, broad detection, and low limits of detection.
Purpose of the Study:
- To demonstrate precise enzyme positioning within block-copolymer brush nanostructures for switchable bioelectrocatalytic sensors.
- To achieve stable biocatalytic activity with a broad detection range and low limit of detection.
Main Methods:
- Enzyme (glucose oxidase) immobilization via re-initiated polymerization of N-isopropylacrylamide (NIPAM) from poly(dimethylaminoethyl methacrylate) (PDMAEMA) blocks.
- Characterization of polymer brush nanostructures using in situ ellipsometry, X-ray photoelectron spectroscopy, grazing angle FTIR, and surface plasmon resonance.
- Electrochemical analysis using cyclic voltammetry and electrochemical impedance spectroscopy.
Main Results:
- Precise control over polymer brush grafting density, thickness, and crosslinking enabled stable enzyme positioning near electrode surfaces.
- Achieved a low limit of detection (23.9 μM) and a broad glucose sensing dynamic range (0.05–12.8 mM).
- Demonstrated a true "OFF" state responsive to pH or thermal stimuli, with sustained performance over multiple switching cycles.
Conclusions:
- Hierarchical biocatalytic polymer brushes offer unique properties for designing responsive biosensors.
- This approach is suitable for creating complex multi-functional gating platforms for biomonitoring.
