Immobilized enzymes play a crucial role in analytical sensing due to their exceptional stability and considerable commercial importance. In this study, a stable Zr-based metal-organic framework (UiO-66-NH) was prepared as an immobilization platform for horseradish peroxidase (HRP) through covalent binding. HRP@UiO-66-NH retained 75% of its activity after 10 cycles. Subsequently, a colorimetric/fluorometric dual-mode sensing strategy using HRP@UiO-66-NH was developed for nitrite detection. HRP@UiO-66-NH facilitated the transformation of the non-colored compound 3,3',5,5'-tetramethylbenzidine (TMB) into its blue oxidized form. When nitrite is added, oxidized TMB (ox-TMB) specifically engaged with nitrite (NO) to generate diazotized TMB, leading to a color shift from blue to yellow. Concurrently, NO reacted with the amino groups of HRP@UiO-66-NH, forming diazonium compounds and suppressing the fluorescence of HRP@UiO-66-NH. The limits of detection were 0.21 μM and 0.19 μM for the colorimetric and fluorometric strategies, respectively. Furthermore, a portable kit for detecting nitrite was created by integrating gelatin with HRP@UiO-66-NH. The kit could visually identify nitrite from 10-400 μM in colorimetric mode and 0-400 μM in fluorometric mode. This method provides an innovative approach for nitrite sensing, paving the way for new research into multifunctional immobilized enzymes and their potential uses in biochemical sensing applications.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d4nr05024j | DOI Listing |
Nanoscale
January 2025
College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China.
Immobilized enzymes play a crucial role in analytical sensing due to their exceptional stability and considerable commercial importance. In this study, a stable Zr-based metal-organic framework (UiO-66-NH) was prepared as an immobilization platform for horseradish peroxidase (HRP) through covalent binding. HRP@UiO-66-NH retained 75% of its activity after 10 cycles.
View Article and Find Full Text PDFAnalyst
January 2025
Department of Pediatric Surgery, The First Affiliated Hospital of Fujian Medical University, 20 Cha-Zhong Road, Taijiang District, Fuzhou 350005, China.
Methods based on enzyme labelling strategies have been widely developed for capacitance immunoassays, but most suffer from low sensitivity and are unfavorable for routine use in the early stages of diagnostics. Herein, we designed a highly efficient capacitance immunosensing method for the low-abundance neuroblastoma biomarker neuron-specific enolase (NSE) using an interdigitated micro-comb electrode. Initially, monoclonal mouse anti-human NSE capture antibodies were immobilized on the interdigitated gold electrodes using bovine serum albumin.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Environment and Resource, Key Laboratory of Solid Waste Treatment and Resource Recycle of Ministry of Education, Southwest University of Science and Technology, Mianyang, Sichuan 621010, China.
Recently, multi-enzyme cascade catalysis has attracted increasing attention due to the advantages of integrating multiple enzymes, few side reactions and high catalytic efficiency. Herein, a novel dual-enzyme cascade system (GOx-FMt-HRP) was developed through cofactor-directed orientational co-immobilization of glucose oxidase (GOx) and horseradish peroxidase (HRP) onto functional montmorillonite (FMt). The presented method realizes the reconstitution of cofactors and apo-enzymes (enzymes without cofactors), which enables enzymes to be immobilized in specific orientations on the support, thereby effectively reducing changes in their conformation.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Life Science, Zhengzhou University, 100 Science Road, Zhengzhou 450001, China. Electronic address:
The treatment of diabetic wounds with bacterial infection is a major challenge in the medical field. Microenvironment-responsive hydrogel dressings have shown great advantages, and photothermal antibacterial therapy is a potential antimicrobial strategy to avoid the generation of resistant bacteria. In this work, a glucose-triggered near-infrared (NIR)-responsive photothermal antibacterial hydrogel was designed and named GOGD based on a cascade reaction of glucose oxidation and polyphenol polymerization.
View Article and Find Full Text PDFAMB Express
January 2025
Parasitology and Animal Diseases Department, Veterinary Research Institute, National Research Centre, El Buhouth St., Dokki, Giza, Egypt.
Cryptosporidium sp. is an obligatory intracellular apicomplexan protozoan parasite that causes a disease called cryptosporidiosis with substantial veterinary and medical importance. Therefore, this study aimed to evaluate an early diagnosis of cryptosporidiosis using the anti-Cryptosporidium parvum oocyst immunoglobulin IgG polyclonal antibodies (anti-C.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!