A Lanthanide Complex Fluorescent Probe for the Detection of Melamine

Area of Science:

• Analytical Chemistry
• Food Science
• Spectroscopy

Background:

• Melamine is illegally added to food products due to its high nitrogen content.
• Direct detection of melamine using fluorescence spectroscopy is challenging due to its weak fluorescence.
• Ensuring food safety requires reliable methods for detecting melamine adulteration.

Purpose of the Study:

• To develop a sensitive fluorescence-based method for detecting melamine.
• To utilize the tetracycline-europium (EuTC) complex as a fluorescent probe for melamine detection.
• To investigate the mechanism behind melamine's fluorescence enhancement of the EuTC complex.

Main Methods:

• Characterization of absorption spectra.
• Analysis of molecular electrostatic potential distribution.
• Time-resolved spectral measurements to study fluorescence enhancement.

Main Results:

• Melamine significantly enhances the EuTC complex's emission at 616 nm.
• A linear relationship was observed between EuTC fluorescence intensity and melamine concentration (0.5–40.0 μM).
• A low detection limit of 7.85 × 10⁻⁸ M was achieved with a correlation coefficient of 0.9951.

Conclusions:

• The EuTC complex serves as a highly sensitive fluorescent probe for melamine detection.
• Hydrogen bonding interactions between tetracycline and melamine are proposed as the mechanism for fluorescence enhancement.
• This method offers a valuable tool for melamine detection in food safety applications, extending fluorescence spectroscopy capabilities.