Polymer Brushes on Silica Nanostructures Prepared by Aminopropylsilatrane Click Chemistry: Superior Antifouling and Biofunctionality
Journal article, 2023

In nanobiotechnology, the importance of controlling interactions between biological molecules and surfaces is paramount. In recent years, many devices based on nanostructured silicon materials have been presented, such as nanopores and nanochannels. However, there is still a clear lack of simple, reliable, and efficient protocols for preventing and controlling biomolecule adsorption in such structures. In this work, we show a simple method for passivation or selective biofunctionalization of silica, without the need for polymerization reactions or vapor-phase deposition. The surface is simply exposed stepwise to three different chemicals over the course of ∼1 h. First, the use of aminopropylsilatrane is used to create a monolayer of amines, yielding more uniform layers than conventional silanization protocols. Second, a cross-linker layer and click chemistry are used to make the surface reactive toward thiols. In the third step, thick and dense poly(ethylene glycol) brushes are prepared by a grafting-to approach. The modified surfaces are shown to be superior to existing options for silica modification, exhibiting ultralow fouling (a few ng/cm2) after exposure to crude serum. In addition, by including a fraction of biotinylated polymer end groups, the surface can be functionalized further. We show that avidin can be detected label-free from a serum solution with a selectivity (compared to nonspecific binding) of more than 98% without the need for a reference channel. Furthermore, we show that our method can passivate the interior of 150 nm × 100 nm nanochannels in silica, showing complete elimination of adsorption of a sticky fluorescent protein. Additionally, our method is shown to be compatible with modifications of solid-state nanopores in 20 nm thin silicon nitride membranes and reduces the noise in the ion current. We consider these findings highly important for the broad field of nanobiotechnology, and we believe that our method will be very useful for a great variety of surface-based sensors and analytical devices.

silanization

silica

antifouling

nanochannels

polymer brushes

nanopores

Author

John Andersson

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Julia Järlebark

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Sriram Kesarimangalam

Chalmers, Life Sciences, Chemical Biology

Andreas Schaefer

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Rebekah Hailes

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Chonnipa Palasingh

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Bagus Santoso

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Van Truc Vu

National Central University

Chun Jun Huang

Chung Yuan Christian University

National Central University

Fredrik Westerlund

Chalmers, Life Sciences, Chemical Biology

Andreas Dahlin

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

ACS Applied Materials & Interfaces

1944-8244 (ISSN) 1944-8252 (eISSN)

Vol. 15 7 10228-10239

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Areas of Advance

Nanoscience and Nanotechnology

Health Engineering

Subject Categories

Physical Chemistry

Materials Chemistry

Other Chemistry Topics

DOI

10.1021/acsami.2c21168

PubMed

36765467

More information

Latest update

4/21/2023