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A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay
Published on: February 28, 2015
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Highly selective, sensitive and simpler colorimetric sensor for Fe2+ detection based on biosynthesized gold
Pirah Siyal1, Ayman Nafady2, Sirajuddin3
1National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080, Pakistan.
Summary
Green bell pepper extract capped gold nanoparticles (CA-AuNPs) were synthesized and used as a sensitive colorimetric sensor. This novel sensor selectively detects Fe2+ in water samples with high accuracy and low detection limits.
Area of Science:
- Nanotechnology and Materials Science
- Environmental Chemistry
- Analytical Chemistry
Background:
- Gold nanoparticles (AuNPs) offer unique optical properties for sensing applications.
- Developing cost-effective and eco-friendly methods for nanoparticle synthesis is crucial.
- Accurate detection of Fe2+ is important for water quality monitoring.
Purpose of the Study:
- To synthesize green bell pepper extract capped gold nanoparticles (CA-AuNPs).
- To develop a sensitive and selective colorimetric sensor for Fe2+ detection.
- To evaluate the sensor's performance in real water samples.
Main Methods:
- Green synthesis of AuNPs using Capsicum annuum L. extract and tetrachloroaurate precursor.
- Characterization using UV-Vis spectroscopy, FTIR, AFM, DLS, and XRD.
- Colorimetric detection of Fe2+ using UV-Vis spectrometry.
Main Results:
- Successful synthesis of ruby-red CA-AuNPs confirmed by SPR at 519 nm.
- The CA-AuNPs sensor showed high sensitivity and selectivity for Fe2+ detection.
- Linear detection range of 0.3-7.0 ppb Fe2+ with LOD of 0.036 ppb and LOQ of 0.12 ppb.
- Effective application in determining Fe2+ in real water samples.
Conclusions:
- Green bell pepper extract is an effective capping agent for gold nanoparticle synthesis.
- CA-AuNPs serve as a highly sensitive and selective colorimetric sensor for Fe2+.
- This method provides a promising approach for environmental water quality assessment.
