A sulfone-based fluorogenic probe for cascade detection of Zn2+ and PO43− ions

Abstract

Detection of trace amounts of metal and non-metal ions is environmentally and biologically significant. In the present contribution, we have introduced a fluorogenic 4,4-diaminodiphenylsulphone-based probe, ASSA, which instantly detects Zn2+ions in its solid and liquid medium. With the implementation of Zn2+ions to the ASSA solution, an instant green fluorescence is observed at 485 nm due to the chelation of Zn2+ ions with ASSA with a stoichiometric ratio of 1:1, evident from the Job's plot and revealed binding constant as 2.6 × 105 M−1. This green fluorescence is reversed in the presence of PO43− ions, proving that our modeled fluorosensor could be a reliable candidate for the cascade detection of Zn2+ and PO43− ions. Along with our modeled fluorosensor, ASSA bears an outstanding selectivity and targeted sensitivity with a detection limit of Zn2+and PO43− ions as 16.65 nM and 0.134 μM, respectively, in a 10 % H2O-DMSO medium. A super handy paper-cuts-based experiment has been performed to recognize and quantify Zn2+ ions in the Cd2+, Hg2+, and other metals crowding situation. Also, we have constructed an INHIBIT logic gate based on the "on-off" fluorescence behavior of ASSA towards Zn2+ ions.