Highly selective and sensitive detection of amaranth by using carbon dots-based nanosensor.

Area of Science:

• Analytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Accurate quantification of food additives like amaranth is crucial for consumer safety and regulatory compliance.
• Existing methods for amaranth detection may lack sensitivity, selectivity, or require complex sample preparation.
• Fluorescence-based nanosensors offer potential for rapid, sensitive, and selective chemical analysis.

Purpose of the Study:

• To develop a novel, highly sensitive, and selective fluorescence nanosensor for amaranth detection.
• To investigate the sensing mechanism of amaranth using carbon dots (C-dots).
• To validate the nanosensor's performance in real-world applications, specifically in beverage analysis.

Main Methods:

• Synthesis of water-soluble, fluorescent carbon dots (C-dots) using a microwave-assisted method with urea and glycine.
• Construction of a fluorescence nanosensor based on the C-dots.
• Investigation of amaranth's effect on C-dots fluorescence, exploring inner filter effect (IFE) and non-radiative energy transfer (NRET) mechanisms.

Main Results:

• The C-dots exhibited strong fluorescence, sensitive to amaranth concentration in the range of 0.2–30 μM.
• A low limit of detection (LOD) of 0.021 μM was achieved for amaranth.
• The nanosensor demonstrated high selectivity, with no significant interference from other substances, and was successfully applied to amaranth analysis in drinks.

Conclusions:

• A novel and efficient fluorescence nanosensor for amaranth detection was successfully developed using carbon dots.
• The C-dots nanosensor operates via fluorescence quenching mechanisms (IFE and NRET) and offers excellent sensitivity and selectivity.
• The developed nanosensor shows significant potential for the rapid, accurate, and sensitive detection of amaranth in real-life food and beverage samples.