Related Experiment Video
Updated: Jul 28, 2026
08:50
Multiplexed Fluorescent Microarray for Human Salivary Protein Analysis Using Polymer Microspheres and Fiber-optic Bundles
Published on: October 10, 2013
Fiber-optic microsensor array based on fluorescent bulk optode microspheres for the trace analysis of silver ions
Katarzyna Wygladacz1, Aleksandar Radu, Chao Xu
1Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA.
Analytical Chemistry
|August 2, 2005
Summary
A novel optical microsensor array offers rapid, highly selective detection of silver ions (Ag+) at ultra-low concentrations. This advancement significantly improves upon existing methods for analyzing trace silver in environmental samples.
Area of Science:
- Analytical Chemistry
- Environmental Science
- Materials Science
Background:
- Accurate detection of trace silver ions (Ag+) is crucial for environmental monitoring and water quality assessment.
- Existing methods for Ag+ detection, such as ion-selective electrodes (ISEs) and optode films, often suffer from slow response times and higher detection limits.
- The ionophore o-xylylenebis(N,N-diisobutyldithiocarbamate) (Cu-I) has been reevaluated and shows high selectivity for silver ions.
Purpose of the Study:
- To develop and characterize a rapid, highly sensitive Ag+-selective fluorescent optical microsensor array.
- To achieve a lower detection limit for Ag+ compared to existing optical sensors and ISEs.
- To demonstrate the application of the microsensor array for real-world sample analysis.
Main Methods:
- Fabrication of micrometer-scale fluorescent microspheres using a sonic particle casting device, incorporating the ionophore Cu-I and other components.
- Optimization of ion-selective electrode (ISE) membranes to achieve low detection limits for Ag+.
- Characterization of the optical microsensor array using fluorescence spectroscopy across a range of Ag+ concentrations (10⁻¹²–10⁻⁸ M) at pH 7.4.
Main Results:
- The optimized ISE membranes exhibited a detection limit of 3 x 10⁻¹⁰ M for Ag+.
- The developed Ag+-selective fluorescent optical microsensor array demonstrated a response time of less than 15 minutes for 10⁻⁹ M Ag+.
- A significantly low detection limit of 4 x 10⁻¹¹ M for Ag+ was achieved, surpassing previous optode and ISE performance.
Conclusions:
- The novel optical microsensor array provides rapid and highly sensitive detection of trace silver ions.
- The microsensor array exhibits superior performance in terms of response time and detection limit compared to existing technologies.
- The developed sensor is suitable for measuring free silver levels in environmental samples, such as buffered pond water.
