Related Experiment Video
Updated: Aug 2, 2026
12:20
Fabrication of Carbon Nanotube High-Frequency Nanoelectronic Biosensor for Sensing in High Ionic Strength Solutions
Published on: July 22, 2013
18.6K
A tunable pH-sensing system based on Ag nanoclusters capped by hyperbranched polyethyleneimine with different
Fei Qu1, Xuan Zou1, Rongmei Kong1
1The Key Laboratory of Life-Organic Analysis, Qufu Normal University, Qufu 273165, Shandong, China; Key Laboratory of Pharmaceutical Intermediates and Analysis of Natural Medicine, Qufu Normal University, Qufu 273165, Shandong, China.
Talanta
|December 24, 2015
Summary
This study presents a tunable pH sensing system using silver nanoclusters (Ag NCs) with polyethyleneimine (PEI). The system offers flexible visual pH indication across various environments, enhancing accuracy and reliability.
Area of Science:
- Nanomaterials Science
- Analytical Chemistry
- Chemical Sensing
Background:
- Developing precise and adaptable pH sensing systems is crucial for diverse scientific applications.
- Existing methods may lack tunability or visual detection capabilities for real-time monitoring.
- Silver nanoclusters (Ag NCs) offer unique optical properties suitable for sensing applications.
Purpose of the Study:
- To develop a tunable pH sensing system based on Ag nanoclusters (Ag NCs) capped by hyperbranched polyethyleneimine (PEI) with varying molecular weights.
- To investigate the pH-dependent optical responses (fluorescence and absorbance) of these Ag NC-PEI systems.
- To establish the feasibility of using these systems as visual pH indicators across different pH ranges.
Main Methods:
- Synthesis of Ag nanoclusters (Ag NCs) functionalized with hyperbranched polyethyleneimine (PEI) of different molecular weights (600, 1800, 25,000, and 70,000 g/mol).
- Characterization of optical properties, including fluorescence intensity and ultraviolet-visible (UV-Vis) absorbance spectra, across a range of pH values.
- Evaluation of color change points and linear sensing ranges for different Ag NC-PEI formulations.
Main Results:
- Tunable linear pH sensing ranges were achieved by varying PEI molecular weights, with specific ranges identified for acid to neutral conditions.
- Ag NC-PEI systems demonstrated distinct color changes at different pH values, enabling visual detection.
- Linear relationships were observed between pH variations and fluorescence intensity, as well as absorbance ratios (A415/A268 nm).
Conclusions:
- The developed Ag NC-PEI system provides a flexible, reliable, and accurate platform for pH sensing.
- The system's tunable nature and multi-modal detection (fluorescence, UV-Vis, visual) make it suitable for diverse environmental applications.
- This tunable pH-sensing platform offers a significant advancement in visual pH indication and chemical sensing technologies.
