Potential of gold nanoparticles for detecting heavy metal under varying conditions

Abstract

Heavy metal contamination has been a global environmental issue, posing severe risks to human health and ecosystems. Conventional detection methods, such as atomic absorption spectroscopy and inductively coupled plasma mass spectrometry, have been costly, time-intensive, and require specialized equipment. Gold nanoparticle (AuNP)--based sensors emerged as an alternative due to their unique optical and chemical properties. These sensors functioned on the principle of localized surface plasmon resonance (LSPR) and colorimetric detection, where interactions with heavy metal ions resulted in the aggregation or dispersion of AuNPs, leading to distinct shifts in absorption spectra. For instance, AuNP-based sensors achieved detection limits as low as 0.1 nM for mercury (Hg²⁺) and 0.5 nM for lead (Pb²⁺), significantly improving sensitivity over traditional methods. Various detection techniques, including spectrophotometry, fluorescence, and electrochemical methods, were employed to quantify these changes. The review discussed the selectivity and sensitivity of different AuNP-based sensors, emphasizing their applications in environmental monitoring, food safety, and biomedical diagnostics. Challenges such as stability, reproducibility, and real-world implementation were addressed, underscoring the necessity for interdisciplinary collaboration. Future advancements in AuNP sensor technology aimed to enhance detection capabilities while ensuring cost-effectiveness and environmental sustainability in tackling heavy metal contamination