Titanium dioxide nanoparticles embedded in assembled dipeptide hydrogels for microfluidic photodegradation

Yue Li; Tianfang Zheng; Yixuan Du; Binyu Zhao; Himanshu P Patel; Regine Boldt; Günter K Auernhammer; Andreas Fery; Junbai Li; Julian Thiele

doi:10.1016/j.jcis.2023.09.191

Titanium dioxide nanoparticles embedded in assembled dipeptide hydrogels for microfluidic photodegradation

J Colloid Interface Sci. 2024 Jan 15;654(Pt A):405-412. doi: 10.1016/j.jcis.2023.09.191. Epub 2023 Oct 1.

Authors

Affiliations

¹ School of Life Sciences, Jilin University, 130012 Changchun, PR China; Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany. Electronic address: liyue90@jlu.edu.cn.
² Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), College of Physics, Jilin University, 130012 Changchun, PR China.
³ Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany.
⁴ Beijing National Laboratory for Molecular Sciences (BNLMS), CAS Key Lab of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, 100190 Beijing, PR China. Electronic address: jbli@iccas.ac.cn.
⁵ Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany; Institute of Chemistry, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany. Electronic address: julian.thiele@ovgu.de.

PMID: 37852026
DOI: 10.1016/j.jcis.2023.09.191

Abstract

Dipeptides can be self-assembled via non-covalent bonds towards functional nanostructures for diverse applications in nanotechnology. Here, we introduce a convenient microfluidics-guided dipeptide design as a platform for photodegradation of contaminants in water. Titanium dioxide (TiO₂) nanoparticles (NPs) are chosen as photocatalysts due to their vastly studied properties. By using a well-defined microchannel architecture, the dipeptide N-fluorenylmethoxycarbonyl diphenylalanine (Fmoc-FF) and TiO₂ NPs are efficiently mixed leading to a self-assembled Fmoc-FF hydrogel with embedded TiO₂. Owing to shear-thinning and rapid self-healing of Fmoc-FF hydrogels, we can transfer and inject Fmoc-FF/TiO₂ hydrogels into any other microdevice for specific applications, where these low-molecular-weight-gelator- (LMWG-)based Fmoc-FF hydrogels fill out the microchannel volume. Different morphologies of Fmoc-FF/TiO₂ hydrogels are obtained by simple concentration screening of TiO₂ NPs and Fmoc-FF. Owing to the density of the three-dimensionally twined Fmoc-FF nanofibers, solutions swelling the dipeptide hydrogel can be exchanged without leaching out TiO₂ NPs. By further analysis, our hydrogel-filled flow cell can be employed for continuous-flow photodegradation in water under light irradiation. Especially, compared to the TiO₂ NPs suspension, Fmoc-FF/TiO₂ hydrogels with relatively low concentrations of TiO₂ exhibit enhanced photodegradation capabilities due to better dispersion of nanoparticles. Such strategy provides a versatile platform for embedment of small inorganic catalysts or enzymes for (bio-)chemical conversion of solutes passing through the hydrogel network.

Keywords: Dipeptide; Hydrogel; Nanotechnology; Self-assembly; Supramolecular assembly.