A ‘on-off-on’ fluorescent probe for sensitive detection of Fe³⁺ and ascorbic acid by cross-linking agent protected carbon dots

ABSTRACT

Carbon dots (CDs) have gained great attention as multifunctional materials because of their interesting properties and general applicability. Herein, new CDs were synthesised from a facile hydrothermal treatment of cysteine and ethylene glycol dimethacrylate as both carbon and nitrogen source and cross-linking agent with high quantum yield (47.2%), respectively. The as prepared CDs were used to detect Fe³⁺ and ascorbic acid. The fluorescence intensity of CDs was selectivity quenched by Fe³⁺ in the range of 0.03–15.0 µM, with a detection limit of 10.2 nM. Meanwhile, ascorbic acid was found to reduce Fe³⁺ to Fe²⁺, thereby causing restoration of the fluorescence of CDs. The detection limit for ascorbic acid detection was estimated as 54.3 nM over a linear range from 0.1 to 25.0 µM. Furthermore, the designed sensing platform was successfully utilised to the detection of Fe³⁺ and ascorbic acid in water and fruits samples.

KEYWORDS:

• Carbon dots
• detection
• Fe³⁺
• ascorbic acid
• river water
• fruits

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

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Additional information

Funding

This research was supported by grants-in-aid for the Tianjin technology demonstration project for integrated development of primary, secondary and tertiary industries (project number:17ZXYENC00010, China) and Gaoyou key research and development projects from Modern Agriculture (project number: GY201812, China).