Nanostructured Poly(ethylene glycol) Diacrylate-Based Hydrogels Printed by Focused Electron Beam-Induced Deposition: Implications for Nanosensors

Hydrogels, especially poly(ethylene glycol)-based hydrogels, have received considerable attention due to their excellent performance. However, the commonly used millimeter or micron size of hydrogels limits their higher resolution sensing applications. Using liquid-phase, focused electron-beam-induced deposition is a feasible way to print nanostructured hydrogels. In this work, a device based on a scanning electron microscope was designed to fabricate nanopatterned hydrogels and the electron scattering distribution to induce hydrogel cross-linking was obtained by an optimized Monte Carlo simulation with a Pearson correlation coefficient analysis. We discuss the factors affecting the swelling ratio of the poly(ethylene glycol)diacrylate hydrogel and conclude that the feature size of the hydrogel is about 280 nm in diameter under certain conditions. This study provides a solution for the miniaturized preparation of nanohydrogels, which will help improve the ability of nanosensors to obtain more high density of arrays.