Development of paper-based detection methods for aqueous Cr(III) utilizing label-free plasmonic AgNPs

Area of Science:

• Nanotechnology
• Environmental Science
• Analytical Chemistry

Background:

• Silver nanoparticles (AgNPs) exhibit unique plasmonic properties.
• Colorimetric detection offers a simple and visual analytical method.
• Chromium(III) is a pollutant requiring sensitive detection methods.

Purpose of the Study:

• To develop a paper-based plasmonic sensor for Cr(III) detection.
• To utilize Ceriops decandra bark extract for AgNP synthesis.
• To validate the sensor's performance for real-world applications.

Main Methods:

• Synthesis of spherical AgNPs using Ceriops decandra extract as a reducing and capping agent.
• Colorimetric detection based on aggregation-induced plasmonic shifts of AgNPs.
• Validation using UV-Vis spectroscopy, SERS, FESEM, TEM, and DLS.

Main Results:

• The sensor demonstrated high selectivity and sensitivity towards Cr(III).
• A linear response was observed for Cr(III) concentrations from 0.1 to 20 nM.
• A low detection limit of 0.1 nM was achieved with R² = 0.9832.

Conclusions:

• The developed method is a label-free, portable, and efficient approach for on-site Cr(III) detection.
• Ceriops decandra extract facilitates the formation of a selective Cr(III) sensor.
• This plasmonic sensing mechanism offers a reliable solution for environmental water analysis.