Sequential multiple-target chemosensor: Co²⁺, Cu²⁺, PPi, and HSˉ discrimination by a bis(half-salamo)-type probe

Abstract

A bis(half-salamo)-type chemosensor L_PBHS based on phenanthroline, which can identify multiple targets continuously, was synthesized. The chemosensor L_PBHS utilizes the N₃O cavities to combine with metal cations, and further identify the anions after the complexes have been formed. The chemosensor L_PBHS has an O-phenanthroline unit with excellent luminescence, so that the strong fluorescence of the chemosensor L_PBHS can be observed under 365 nm UV light. The quenching of luminescence occurs after the introduction of Cu²⁺ and Co²⁺ into the chemosensor L_PBHS, which can be identified in natural light by observing the change in color of the solution with the naked eye. The L_PBHS-Cu²⁺ complex further recognizes HSˉ and PPi (pyrophosphoric acid), and strong luminescence are also observed under UV light after the addition of HSˉ and PPi to L_PBHS-Cu²⁺. HSˉ and PPi can also be identified by the change in color of the solution under natural light with the naked eye. Using the strong fluorescence emission of L_PBHS, a test strip was developed to detect Cu²⁺ and Co²⁺ rapidly, and the quenching of fluorescence was clearly observed under UV light. HSˉ and PPi can be further identified by the phenomenon of fluorescence recovery after Cu²⁺ detection on the test strip.

Graphical Abstract

Keywords:

• Chemical probe
• test strip
• sequential multiple-target discrimination
• bis(half-salamo)-type tetraoxime

Declarations of interest

The authors declare no conflict of interest.

Additional information

Funding

This work was supported by Gansu Science and Technology Planning Program (No.20JR2RA002) and the Open Foundation of Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou Jiaotong University (No.21YRWEK004), two of which are gratefully acknowledged.