Optical devices were fabricated by sandwiching a "monolithic" poly(N-isopropylacrylamide-co-N-(3-aminopropyl) methacrylamide hydrochloride) (pNIPAm-co-APMAH) microgel layer between two semitransparent Au layers. These devices, referred to as etalons, exhibit characteristic multipeak reflectance spectra, and the position of the peaks in the spectra primarily depends on the distance between the Au surfaces mediated by the microgel layer thickness. Here, we show that the positively charged microgel layer can collapse in the presence of negatively charged single stranded DNA (ssDNA) due to ssDNA induced microgel crosslinking. The collapse results in a change in the etalon's optical properties, which can be used to detect target DNA in a complex mixture.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.aca.2014.06.038 | DOI Listing |
ACS Mater Au
January 2025
Faculty of Chemistry, University of Warsaw, 1 Ludwika Pasteura Str., PL 02-093 Warsaw, Poland.
In this study, we demonstrate the formation of a self-assembled microgel double layer on an electrode surface, utilizing the ability to form electro-responsive, reversible inclusion complexes between microgels modified with ferrocene and β-cyclodextrin in these systems. The bottom layer was based on microgels containing ferrocene moieties and derivatives of cysteine. The presence of the amino acid derivative enabled the formation of the well-packed monolayer on the gold surface through chemisorption, while ferrocene was responsible for electroactivity.
View Article and Find Full Text PDFAdv Mater
December 2024
Dynamic Colloidal Systems Laboratory, Department of Chemistry, Indian Institute of Technology, Roorkee, 247667, India.
The design of chemomechanical self-oscillators, which execute oscillations in the presence of constant stimuli lacking periodicity, is a step toward the development of autonomous and interactive soft robotic systems. This work presents a simple design of prolonged chemomechanical oscillatory movement in a microgel system capable of buoyant motility within stratified chemical media containing spatially localized sinking and floating stimuli. Three design elements are developed: a stimuli-responsive membranized calcium alginate microgel, a Percoll density gradient for providing stratified antagonistic chemical media, and transduction of microgel particle size actuation into buoyant motility via membrane-mediated displacement of the Percoll media.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
School of Chemistry and Chemical Engineering, North University of China, NO. 3 Xueyuan Road, Jiancaoping District, Taiyuan 030051, China. Electronic address:
The spontaneous self-organization of naturally-occurring polysaccharide particles into a thick and robust gel network at interface in Pickering emulsion is challenging. Inspired by the phenomenon that chitosan microgels (CSMs) with a certain size could self-associate into a solidified gel phase upon freezing, here we tentatively used CSMs to construct a highly-stable Pickering emulsion. CSMs can form a stable Langmuir's layer at the water/oil interface through the network deformation and re-arrangement of dangling chains, while the subsequent negative polymer coating can avoid the bridging resulting from the cross-association for CSMs on different emulsion droplets upon freezing.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources, College of Chemistry, Xinjiang University, Urumqi 830017, Xinjiang, PR China.
Polylactic acid (PLA) can serve as a biodegradable alternative to traditional petroleum-based plastics, but its poor impact resistance and high production costs limit its applications. In this study, different contents of epoxidized epoxy soybean oil (ESO) were added as plasticizer to melt blend with polylactic acid (PLA), polypropylene (PP) and cotton stalk fiber (CSF), examining its impact on the mechanical properties, thermal stability, microstructure, and crystallization behavior of the blends. The results indicated that ESO reacted with PLA and CSF to form branched polymers and microgels.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
February 2025
Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan. Electronic address:
For enzyme-based electrochemical devices, an improvement in electron transfer between the enzyme and electrode is important. Thus, we developed a nano-scaled hydrogel that includes an electron mediator and enzyme to realize nano-sized effects that enhance the functions. Three different chain lengths (short, medium, and long) of copolymers composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid N-hydroxysuccinimide ester (MNHS; poly(MPC-co-MNHS), PMS) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!