Enzyme Immobilization in Polyelectrolyte Brushes: High Loading and Enhanced Activity Compared to Monolayers
Artikel i vetenskaplig tidskrift, 2019

Catalysis by enzymes on surfaces has many applications. However, strategies for efficient enzyme immobilization with preserved activity are still in need of further development. In this work, we investigate polyelectrolyte brushes prepared by both grafting-to and grafting-from with the aim to achieve high catalytic activity. For comparison, self-assembled monolayers that bind enzymes with the same chemical interactions are included. We use the model enzyme glucose oxidase and two kinds of polymers: anionic poly(acrylic acid) and cationic poly(diethylamino)methyl methacrylate. Surface plasmon resonance and spectroscopic ellipsometry are used for accurate quantification of surface coverage. Besides binding more enzymes, the "3D-like" brush environment enhances the specific activity compared to immobilization on self-assembled monolayers. For grafting-from brushes, multilayers of enzymes were spontaneously and irreversibly immobilized without conjugation chemistry. When the pH was between the pI of the enzyme and the pK a of the polymer, binding was considerable (thousands of ng/cm 2 or up to 50% of the polymer mass), even at physiological ionic strength. However, binding was observed also when the brushes were neutrally charged. For acidic brushes (both grafting-to and grafting-from), the activity was higher for covalent immobilization compared to noncovalent. For grafting-from brushes, a fully preserved specific activity compared to enzymes in the liquid bulk was achieved, both with covalent (acidic brush) and noncovalent (basic brush) immobilization. Catalytic activity of hundreds of pmol cm -2 s -1 was easily obtained for polybasic brushes only tens of nanometers in dry thickness. This study provides new insights for designing functional interfaces based on enzymatic catalysis.

Spectroscopic ellipsometry

Enzyme immobilization

Enzyme activity

Catalysis

Författare

Gustav Ferrand Drake Del Castillo

Chalmers, Kemi och kemiteknik, Kemiteknik

Meike Koenig

Leibniz-Institut fur Polymerforschung

Karlsruher Institut für Technologie (KIT)

Martin Müller

Technische Universität Dresden

Leibniz-Institut fur Polymerforschung

Klaus Jochen Eichhorn

Leibniz-Institut fur Polymerforschung

Manfred Stamm

Technische Universität Dresden

Leibniz-Institut fur Polymerforschung

Petra Uhlmann

University of Nebraska - Lincoln

Leibniz-Institut fur Polymerforschung

Andreas Dahlin

Chalmers, Kemi och kemiteknik, Tillämpad kemi, Andreas Dahlin Group

Langmuir

07437463 (ISSN) 15205827 (eISSN)

Vol. 35 9 3479-3489

Ämneskategorier

Polymerkemi

Analytisk kemi

Biokatalys och enzymteknik

DOI

10.1021/acs.langmuir.9b00056

PubMed

30742441

Mer information

Senast uppdaterat

2019-04-08