Label-Free Aptamer-Silver Nanoparticles Abs Biosensor for Detecting Hg².

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Biomedical Engineering

Background:

• Silver nanoparticles (AgNPs) exhibit strong surface plasmon resonance (SPR) absorption.
• AgNP aggregation in salt solutions causes noticeable color changes.
• Aptamers (Apt) can stabilize AgNPs by adsorbing onto their surface.

Purpose of the Study:

• To develop a simple, rapid, and sensitive method for mercury ion (Hg2+) detection.
• To utilize the colorimetric changes of AgNPs induced by Hg2+-aptamer interactions.
• To construct a novel absorbance-based sensing platform for heavy metal detection.

Main Methods:

• Synthesis of stable silver nanoparticles (AgNPs) using light-wave technology.
• Stabilization of AgNPs with aptamers (Apt) to prevent aggregation.
• Detection of mercury ions (Hg2+) based on the color change of the AgNP-Apt system upon Hg2+ binding.

Main Results:

• The AgNP-Apt system demonstrated stability in salt solutions.
• Mercury ions (Hg2+) disrupted the Apt-AgNP interaction, causing a color change.
• The method achieved a linear detection range of 2.5 × 10^-3–10.00 μmol/L for Hg2+.
• A low detection limit (DL) of 2.03 nmol/L for Hg2+ was established.

Conclusions:

• A stable AgNP-Apt system was successfully synthesized.
• The developed system provides a simple and rapid colorimetric method for Hg2+ detection.
• The high sensitivity and low detection limit make this method suitable for practical Hg2+ analysis.