Abstract: Heavy metal ions can enter the human body through foods, air and drinking water. They are non-degradable and can accumulate in living organisms, posing a serious threat to the environment and human health. As the methods traditionally used for the detection of heavy metal ions are cumbersome, time consuming, costly, and poorly portable, it is of great significance to develop quick, convenient and on-site detection methods. In addition to the characteristics of general nano-materials such as specific surface effect and quantum size effect, gold nanoparticles (GNPs) also have good biocompatibility and unique optical properties, thereby showing great application prospects in the detection of heavy metal ions. In this paper, we summarize the methods for the synthesis of several typical GNPs, and we review recent progress in applying surface plasmon resonance (SPR), dynamic light scattering, surface-enhanced Raman scattering, surface-enhanced fluorescence, gold test strip and GNPs chiral sensing technology in the detection of heavy metal ions based on the optical properties of GNPs. The principles of these technologies as well as their advantages and drawbacks are analyzed in order to provide useful information for the detection of heavy metal ions in foods, the environment, drinking water and specific samples.

Key words: gold nanoparticles, synthesis, optical properties, heavy metal ion detection