Highly selective and sensitive fluorescent probe for the detection of nitrite

Area of Science:

• Analytical Chemistry
• Chemical Sensing
• Fluorescence Spectroscopy

Background:

• Nitrite (NO2(-)) is an important analyte in environmental and food safety.
• Development of selective and sensitive probes for nitrite detection remains a challenge.

Purpose of the Study:

• To develop a simple and reliable fluorescent probe for sensitive and selective detection of nitrite (NO2(-)).
• To investigate the sensing mechanism and evaluate the probe's performance in real-world samples.

Main Methods:

• Rationally designed and synthesized a fluorescent probe, 2-(1H-phenanthro[9,10-d] imidazol-2-yl)aniline (PA).
• Utilized NMR, IR spectroscopy, control experiments, and DFT calculations to elucidate the sensing mechanism.
• Determined the linear response range and detection limit for nitrite.
• Applied the probe to analyze nitrite in environmental and food samples.

Main Results:

• The PA probe exhibited a novel sensing mechanism based on NO2(-)-mediated diazozation and cyclization.
• The probe demonstrated low pH dependence, fast response, and high selectivity for nitrite over other species.
• Achieved a linear response range of 0.1-10 μM for nitrite with a low detection limit of 4.3×10(-8) M.
• Successfully applied the PA probe for the determination of nitrite in environmental and food products.

Conclusions:

• The developed PA probe is a simple, reliable, and highly sensitive tool for fluorescent detection of nitrite.
• The probe's selectivity and applicability to real samples make it a promising candidate for nitrite monitoring.