New Fluorescent Sensor Detects Mercury and Iron in Vetiver Grass and Spinach

Jenn Hoskins
17th July, 2024

New Fluorescent Sensor Detects Mercury and Iron in Vetiver Grass and Spinach

Scanning electron microscopy images reveal that the original rod-like morphology of the LUS-1 mesoporous silica (a) is successfully preserved after functionalization to create the DAN-LUS-1 fluorescence probe (b).

Image adapted from: Nouri et al. / CC BY (Source)

Key Findings

  • Researchers at Islamic Azad University, Tehran, Iran, developed a new fluorescence probe to detect mercury (Hg2+) and iron (Fe3+) ions in food samples
  • The probe, made from mesoporous silica functionalized with 1,8-diaminonaphthalene, showed high sensitivity and selectivity for detecting these heavy metals
  • The probe successfully measured Hg2+ and Fe3+ levels in vetiver grass and spinach, demonstrating its practical application for monitoring heavy metal pollution in food
Heavy metal pollution is a significant environmental problem, posing risks to both ecosystems and human health. Detecting these pollutants accurately and efficiently is crucial for mitigating their harmful effects. Fluorescence-based detection methods are particularly effective due to their sensitivity and selectivity. In a recent study conducted by researchers at Islamic Azad University, Tehran, Iran, a novel fluorescence probe was developed to detect mercury (Hg2+) and iron (Fe3+) ions in food samples[1]. The study focused on synthesizing a super-stable mesoporous silica, functionalized with 1,8-diaminonaphthalene (DAN-LUS-1), to serve as a fluorescence probe. The researchers utilized various analytical techniques to confirm the successful grafting of 1,8-diaminonaphthalene onto LUS-1. Thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FT-IR) illustrated the incorporation of 1,8-diaminonaphthalene. X-ray diffraction (XRD) patterns verified the hexagonal symmetrical array of nano-channels in both LUS-1 and DAN-LUS-1. Scanning electron microscopy (SEM) images showed that the rod-like morphology of LUS-1 was preserved after functionalization. Additionally, nitrogen adsorption-desorption isotherms revealed a decrease in surface area and pore diameter, indicating successful immobilization of 1,8-diaminonaphthalene into the pores of LUS-1. The fluorescence properties of DAN-LUS-1 were studied using a 340/407 nm excitation/emission wavelength, which was quenched by the presence of Hg2+ and Fe3+ ions. The fluorescence response allowed for the quantification of these ions within specific working ranges, with detection limits of 8.5 × 10-8 M for Hg2+ and 1.3 × 10-7 M for Fe3+. The probe demonstrated its practical application by measuring Hg2+ and Fe3+ levels in vetiver grass and spinach samples. The study also explored a circuit logic system using Fe3+, Hg2+, and sodium hexametaphosphate (SHMP) as inputs, with the fluorescent quench as the output. The findings of this study are significant when considering previous research on heavy metal toxicity. For instance, a study on the effects of low-dose metal mixtures on mice revealed that combinations of heavy metals such as lead (Pb), mercury (Hg), cadmium (Cd), and arsenic (As) induced higher toxicities compared to individual metals[2]. This underscores the importance of detecting multiple heavy metals simultaneously, as their combined effects can be more detrimental to health. Moreover, the detection of Fe3+ is particularly relevant given its association with iron-deficiency anemia, especially in children with type 1 diabetes[3]. A study found that children with newly diagnosed type 1 diabetes exhibited significantly lower concentrations of hematocrit (HCT) and hemoglobin (HGB), along with reduced red blood cell (RBC) count and mean corpuscular volume (MCV), compared to children who had the disease for a longer duration. The early detection of Fe3+ can thus play a crucial role in preventing and managing iron-deficiency anemia in vulnerable populations. The development of the DAN-LUS-1 fluorescence probe offers a promising solution for the rapid and sensitive detection of Hg2+ and Fe3+ in food samples, addressing the need for effective monitoring of heavy metal pollution. By incorporating advanced analytical techniques and leveraging the unique properties of mesoporous silica, the researchers have created a tool that can help mitigate the risks associated with heavy metal exposure. This study not only builds on previous findings but also provides a practical application for improving public health and environmental safety.

EnvironmentBiochemPlant Science

References

Main Study

1) Diaminonaphthalene functionalized LUS-1 as a fluorescence probe for simultaneous detection of Hg2+ and Fe3+ in Vetiver grass and Spinach.

Published 16th July, 2024

https://doi.org/10.1038/s41598-024-66453-8

Related Studies

2) Toxicity assessment due to sub-chronic exposure to individual and mixtures of four toxic heavy metals.

https://doi.org/10.1016/j.jhazmat.2015.03.057

3) The occurrence of iron-deficiency anemia in children with type 1 diabetes.

https://doi.org/10.1097/JIM.0000000000000098


Related Articles

An unhandled error has occurred. Reload 🗙