Practical immune-barometer sensor for trivalent chromium ion detection using gold core platinum shell nanoparticle...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biotechnology

Background:

• Biosensors have advanced healthcare and environmental monitoring but lack sensitive, portable, and affordable on-site detection methods.
• Detecting heavy metals like chromium(III) in water is crucial for environmental and public health.
• Existing methods like ELISA can be less sensitive, more costly, and not portable for field use.

Purpose of the Study:

• To develop a portable, feasible, and miniaturized immune-barometer sensor (IBS) for sensitive on-site detection of chromium(III).
• To integrate a competitive immunoassay with a pressure-signal-generating system for Cr(iii) quantification.
• To evaluate the performance of the IBS in terms of sensitivity, specificity, and recovery in real water samples.

Main Methods:

• Fabrication of Au@PtNPs (gold core platinum shell nanoparticles) to catalyze H2O2 decomposition, producing O2 gas.
• Utilizing a sealed chamber and a sensitive barometer to measure pressure changes (ΔP) generated by O2 expansion.
• Implementing a competitive immunoassay format for Cr(iii) detection, where ΔP correlates with Cr(iii) concentration.

Main Results:

• The IBS demonstrated a strong correlation between pressure changes (ΔP) and Cr(iii) concentrations in the range of 0.39 to 25 ng mL⁻¹.
• Achieved a low limit of detection (LOD) of 0.35 ng mL⁻¹ for Cr(iii).
• Showcased high specificity and recovery rates (95.6%-110.2%) in tap and river water samples.

Conclusions:

• The developed immune-barometer sensor (IBS) is a sensitive, low-cost, and portable platform for on-site Cr(iii) detection.
• The IBS offers advantages over traditional methods like ELISA for heavy metal analysis in aqueous solutions.
• This technology holds significant potential for environmental monitoring and other bioanalytical applications.