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Published on: September 11, 2020
Hydrogen-bonding recognition-induced aggregation of gold nanoparticles for the determination of the migration of
Long Wu1, Kun Chen1, Zhicheng Lu1
1State Key Laboratory of Agricultural Microbiology, College of Science, Huazhong Agricultural University, Wuhan 430070, PR China.
Abstract:
The migration of melamine monomers from food contact materials has aroused particular attention since the 2008 melamine-tainted milk scandal in China. However, the determination of melamine monomer's migratory quantity (MMMQ) has remained an open question because of the complex sample pretreatment and the low sensitivity. Based on the hydrogen bonding interaction between DNA thymine and melamine, this paper described a simple and rapid method focusing on the measurement of MMMQ from melamine tableware by gold nanoparticles (GNPs) and dynamic light scattering (DLS). With the presence of probe DNA (p-DNA), the GNPs were stable in NaCl solution (0.06 M), whereas they became aggregated when the p-DNA hybridized with melamine. The change in the hydrodynamic diameter of GNPs could be detected by DLS technology. Under the optimal conditions, the average diameter increased linearly with the concentration of melamine over the range from 5.0 to 320.0 μg L(-1), and showed a detection limit of 2.0 μg L(-1) (3σ/slope). The MMMQ was investigated within a range from 6.00×10(-4) to 2.58×10(-1) mg dm(-2) (n≥3) in four different food simulants at different temperatures and time points. The results suggest that the DLS method has great potential in the analysis of the migration of melamine monomers.
Insights
A new method uses gold nanoparticles and DNA to quickly measure melamine migration from tableware. This technique offers a sensitive and simple approach for detecting melamine monomer
Area of Science:
- Analytical Chemistry
- Materials Science
Background:
- Melamine migration from food contact materials is a concern following the 2008 scandal.
- Accurate determination of melamine monomer's migratory quantity (MMMQ) is challenging due to complex pretreatment and low sensitivity.
Purpose of the Study:
- To develop a simple, rapid, and sensitive method for measuring MMMQ from melamine tableware.
- To utilize the hydrogen bonding interaction between DNA thymine and melamine for detection.
Main Methods:
- Employing gold nanoparticles (GNPs) and dynamic light scattering (DLS) for detection.
- Utilizing probe DNA (p-DNA) that aggregates GNPs upon hybridization with melamine.
- Measuring changes in GNP hydrodynamic diameter via DLS.
Main Results:
- The method demonstrated a linear increase in GNP diameter with melamine concentration (5.0–320.0 μg L⁻¹).
- A low detection limit of 2.0 μg L⁻¹ (3σ/slope) was achieved.
- MMMQ was successfully quantified in food simulants under various conditions, ranging from 6.00×10⁻⁴ to 2.58×10⁻¹ mg dm⁻².
Conclusions:
- The developed DLS method provides a simple and rapid approach for MMMQ analysis.
- This technique shows significant potential for routine monitoring of melamine migration from tableware.
- The method overcomes limitations of complex sample pretreatment and low sensitivity in previous methods.
