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A Method for Selecting Structure-switching Aptamers Applied to a Colorimetric Gold Nanoparticle Assay
Published on: February 28, 2015
Gold nanoparticle-based simple colorimetric and ultrasensitive dynamic light scattering assay for the selective
Lule Beqa1, Anant Kumar Singh, Sadia Afrin Khan
1Department of Chemistry, Jackson State University, Jackson, Mississippi, United States.
Insights
A new gold nanoparticle probe detects lead (Pb(II)) in water at ultra-low levels, crucial for public health and environmental safety. This sensitive assay identifies lead in everyday items like toys and paints.
Area of Science:
- Nanotechnology
- Environmental Science
- Analytical Chemistry
Background:
- Lead (Pb(II)) is a toxic water pollutant with significant public health implications, especially for children.
- Existing detection methods lack the sensitivity required for trace amounts of lead in consumer products and water sources.
- There is a critical need for rapid, ultrasensitive, and selective assays for real-time lead detection.
Purpose of the Study:
- To develop a label-free, highly selective, and ultrasensitive probe for detecting lead (Pb(II)) in aqueous solutions.
- To achieve real-time detection of Pb(II) at parts per trillion (ppt) levels.
- To demonstrate the assay's capability in analyzing real-world samples, including water, paint, and plastic toys.
Main Methods:
- Utilized a glutathione-modified gold nanoparticle-based dynamic light scattering (DLS) probe.
- Employed a label-free detection strategy for direct Pb(II) recognition.
- Validated the assay's performance using spiked water samples and environmental matrices (paint, plastic toys, river water).
Main Results:
- The DLS probe achieved ultrasensitive detection of Pb(II) down to 100 ppt, significantly exceeding EPA standard limits.
- Demonstrated excellent selectivity, discriminating Pb(II) effectively against other heavy metals.
- Successfully quantified Pb(II) levels in diverse real-world samples, including consumer products and river water.
Conclusions:
- The developed nanotechnology-driven DLS assay offers a highly sensitive and selective method for Pb(II) detection.
- This assay has significant potential for rapid, on-site monitoring of lead contamination in various environmental and consumer settings.
- The findings support the application of advanced nanomaterials for critical public health and environmental monitoring tasks.
Abstract:
Pb (II) is a common water pollutant with high toxicity. According to the CDC, about 310,000 U.S. children of ages 1-5 have high levels of lead in their blood that it is due to the exposure to lead from plastic toys and other products. As a result, the development of ultrasensitive assays for the real-time detection of Pb(II) from plastic toys and paints is very important for water controlling, clinical toxicology and industrial processes. Driven by the need to detect trace amounts of Pb(II) from water samples, we report a label-free, highly selective and ultra sensitive glutathione modified gold nanoparticle based dynamic light scattering (DLS) probe for Pb(II) recognition in 100 ppt level from aqueous solution with excellent discrimination against other heavy metals. The sensitivity of our assay to detect Pb(II) level in water is almost 2 orders of magnitude higher than the EPA standard limit. We have also demonstrated that our DLS assay is capable of measuring the amount of Pb(II) in paint, plastic toys, and water from MS river. A possible mechanism and operating principles of our DLS assay have been discussed. Ultimately, this nanotechnology driven assay could have enormous potential applications in rapid, on-site monitoring of Pb(II) from day-to-day sample.
