Polyelectrolyte brushes can be utilized to immobilize enzymes on macroscopic surfaces. This report investigates the influence of the pH value of the surrounding medium on the amount and the activity of enzymes adsorbed to poly(2-vinylpyridine) and poly(acrylic acid) brushes, as well as the creation of thermoresponsive biocatalytically active coatings via the adsorption of enzymes onto a mixed brush consisting of a polyelectrolyte and temperature-sensitive poly(N-isopropylacryl amide). Spectroscopic ellipsometry and attenuated total reflection-Fourier transform infrared spectroscopy are used to monitor the adsorption process. Additionally, infrared spectra are evaluated in terms of the secondary structure of the enzymes. Glucose oxidase is used as a model enzyme, where the enzymatic activity is measured after different adsorption conditions. Poly(acrylic acid) brushes generally adsorb larger amounts of enzyme, while less glucose oxidase is found on poly(2-vinylpyridine), which however exhibits higher specific activity. This difference in activity could be attributed to a difference in secondary structure of the adsorbed enzyme. For glucose oxidase adsorbed to mixed brushes, switching of enzymatic activity between an active state at 20°C and a less active state at 40°C as compared to the free enzyme in solution is observed. However, this switching is strongly depending on pH in mixed brushes of poly(acrylic acid) and poly(N-isopropylacryl amide) due to interactions between the polymers.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.colsurfb.2016.07.015DOI Listing

Publication Analysis

Top Keywords

polyacrylic acid
12
glucose oxidase
12
adsorption enzymes
8
acid brushes
8
polyn-isopropylacryl amide
8
secondary structure
8
enzymatic activity
8
enzyme glucose
8
mixed brushes
8
active state
8

Similar Publications

Emergency bleeding presents significant challenges such as high blood flow and rapid hemorrhaging. However, many existing hemostatic bandages face limitations, including the uncontrolled release of hemostatic agents, insufficient mechanical strength, poor adhesion, and complex manufacturing processes. To address these limitations, we developed a multifunctional hydrogel bandage for emergency hemostasis using a one-pot synthesis method.

View Article and Find Full Text PDF

With the rapid development of wearable electronic devices, flexible supercapacitors have gained strong interest. However, traditional sandwich supercapacitors have weak interfacial binding, resulting in high interface resistance and poor deformability. Herein, a self-healing integrated supercapacitor based on a polyacrylic acid-polyisodecyl methacrylate-CoSO gel polymer electrolyte (GPE) was developed.

View Article and Find Full Text PDF

Facile preparation of a hydrophilic Eu-based ratiometric fluorescent nanosensor for Cu ion detection and imaging in living cells.

Anal Methods

January 2025

Key Laboratory of Combinatorial Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430072, China.

In this work, a hydrophilic Eu-based ratiometric fluorescent nanosensor (PAAC-Eu) was developed for Cu ion detection in aqueous solutions and imaging in living cells. The sensor was prepared a simple one-step reaction at room temperature, leveraging the synergistic coordination of commercially accessible polyacrylic acid (PAA) and coumarin-3-carboxylic acid (CCAH) with Eu ions. PAAC-Eu was easy to disperse in aqueous media and exhibited two characteristic emission bands at 406 nm and 618 nm, respectively, upon excitation at 350 nm.

View Article and Find Full Text PDF

A H2S-activated NIR-II imaging probe for precise diagnosis and pathological evaluation of colorectal tumor.

Theranostics

January 2025

Lab of Molecular Imaging and Translational Medicine (MITM), Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, School of Life Science and Technology, Xidian University & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, Xi'an, Shaanxi, 710126, P. R. China.

The quick and accurate detection of colorectal cancer (CRC) is essential for improving the treatment efficacy and patient survival, which nevertheless remains challenging due to low specificity and sensitivity of current CRC diagnostic approaches. Therefore, providing a robust solution for real-time and accurate tumor delineation is highly desirable. We report a novel polyacrylic acid-mediated strategy to develop the endogenous hydrogen sulfide (HS)-activated NIR-II probe DCNP@PB for specific visualization of CRC and image-guided tumor surgery.

View Article and Find Full Text PDF

Microenvironmental modulation breaks intrinsic pH limitations of nanozymes to boost their activities.

Nat Commun

December 2024

College of Engineering and Applied Sciences, Nanjing National Laboratory of Microstructures, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing, Jiangsu, China.

Functional nanomaterials with enzyme-mimicking activities, termed as nanozymes, have found wide applications in various fields. However, the deviation between the working and optimal pHs of nanozymes has been limiting their practical applications. Here we develop a strategy to modulate the microenvironmental pHs of metal-organic framework (MOF) nanozymes by confining polyacids or polybases (serving as Brønsted acids or bases).

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!