A novel copper ion sensing fluorescent probe for fast detection of pyrophosphate and alkaline phosphatase

• Published in: New journal of chemistry Vol. 45; no. 7; pp. 3727 - 3734
• Main Authors: Chen, Lei, Qi, Wenjing, Du, Chengpei, Wang, Yi, Liu, Chun, Huang, Xiaomei, Chang, Xiaojuan
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 22.02.2021
• Subjects: Alkaline phosphatase; Chemical synthesis; Coordination; Copper; Fluorescent indicators; Phosphatase; Proline; Quenching; Selectivity; Tomography
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d1nj00075f

A fluorescent probe with high selectivity for the detection of copper ions (Cu 2+ ) is synthesized using 4-hydroxyhypoxidone, paraformaldehyde and proline via a one-step Mannich reaction. This Cu 2+ fluorescent probe with large Stokes shift (129 nm) has good water solubility and could coordinate with Cu 2+ . It achieves fluorescence of this probe to be quenched linearly with the increasing concentration of Cu 2+ from 10 to 800 nM. Since Cu 2+ and pyrophosphate (PPi) have a stronger coordination ability, it promotes Cu 2+ to coordinate with PPi preferentially and results in the fluorescence of the system being enhanced again. In this way, a novel fluorescence "turn-on" detection of PPi in the range from 2 to 40 μM within 2 min is developed using this Cu 2+ fluorescent probe. It exhibits high selectivity in PPi detection towards other anions such as Cl − , NO 3 − , CO 3 2− , PO 4 3− and SO 4 2− . It is worth noting that PPi can be hydrolyzed into phosphate (Pi) by alkaline phosphatase (ALP), and the coordination between Cu 2+ and Pi is not as strong as that with the probe. Herein the fluorescence of the system can be quenched again after the addition of ALP. A fluorescence "turn-off" detection of ALP from 10 to 90 mU L −1 is achieved using this Cu 2+ fluorescent probe. When it is used to detect ALP in serum samples, recoveries from 98.5% to 104.2% are obtained. A Cu 2+ sensing fluorescent probe is synthesized via a Mannich reaction and is applied in the fluorescence detection of pyrophosphate and alkaline phosphatase.