Portable solid sensor supported in nylon for silver ion determination: testing its liberation as biocide.

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Silver ions are widely used as catalysts and biocides.
• Accurate detection of silver ions at low concentrations is crucial for environmental and industrial monitoring.
• Existing methods for silver ion detection can be complex or require specialized equipment.

Purpose of the Study:

• To fabricate and characterize a novel solid-state optical sensor for the sensitive quantification of silver ions.
• To optimize the sensor's performance for detecting silver ions at micromolar levels.
• To demonstrate the sensor's utility in analyzing real-world water samples.

Main Methods:

• Fabrication of a nylon membrane incorporating pyrogallol red (PGR) and 1,10-phenanthroline (Phen).
• Optimization of reaction parameters for silver-catalyzed oxidation of PGR by persulfate, activated by Phen.
• Utilizing diffuse reflectance (DR) measurement and a smartphone-based digital image-processing tool (GIMP) for quantitative analysis.

Main Results:

• The sensor demonstrated a linear response to Ag(I) concentrations from 0.4 to 10 μM and 1 to 25 μM.
• Achieved limits of detection as low as 0.1 μM with a 50-min incubation time.
• Showcased high reproducibility with a relative standard deviation of approximately 2% across sensor batches.
• Successfully analyzed silver ions in tap water and refrigerating circuit water samples.

Conclusions:

• The developed solid-state optical sensor offers a sensitive, portable, and sustainable method for silver ion quantification.
• The sensor is effective in real-world applications, particularly for monitoring water systems treated with silver-based biocides.
• This technology provides a cost-effective alternative for on-site silver ion analysis.