A New Thiophene-based Aggregation-induced Emission Chemosensor for Selective Detection of Zn<sup>2+</sup> Ions and Its Turn Off
Dulal Musib, Longjam Reena Devi, Md Kausar Raza, S. Binita Chanu, Mithun Roy
Abstract
A new thieno[2,3-b]thiophene-based fluorescent probe (L1) was synthesized and characterized for selective detection of Zn2+ ion at physiological pH. The probe exhibited remarkable “TURN-ON” emission in the presence of mobile Zn2+ ion. Q-TOF ESI mass spectral analysis and Job’s plot confirm 1:1 complex formation with the binding constant, Kb = 1.9 × 104 M−1. Later the 1:1 complex aggregated into a complex structure which was evident from a remarkable enhancement of fluorescence of the probe in the presence of excess of Zn2+ ions. Disodium salt of ethylenediaminetetraacetic acid (Na2H2EDTA) resulted in the TURN-OFF fluorescence of L1:Zn2+ aggregate which led us to formulate a logic-gate circuit for potential biological and material sensing.