Rapid redox-response featured visual ascorbic acid sensor based on simple-assembled europium metal-organic framework.

A facile, fast and visible sensing platform for ascorbic acid (AA) detection has been developed based on self-assembled hydrangea-like europium metal-organic framework (HL-EuMOF). HL-EuMOF was synthesized through a simple one-step mixing process with Eu ³⁺ and 1, 10-phenanthroline-2, 9-dicarboxylic acid at room temperature, which exhibited excellent properties including strong red fluorescence, long decay lifetime (548.623 μs) and good luminescent stability. Based on the specific redox reaction between Fe ³⁺ and AA, the HL-EuMOF@Fe ³⁺ was fabricated with "turn-off" response for AA, where the resulting Fe ²⁺ displayed effective fluorescence quenching ability toward HL-EuMOF. The sensor demonstrated low detection limit (31.94 nM), rapid response time (30 s) and high selectivity. Integration of smartphone-assisted RGB analysis with HL-EuMOF@Fe ³⁺ permitted convenient and visible quantitative determination of AA level. This approach also presented good detection performances in complex human serum and beverage samples, which could provide a valuable tool for AA detection in biomedical research and food industry.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023. Published by Elsevier Ltd.)