Aim: Selective and sensitive visual detection of Cu2+in aqueous solution at PPB level using easily synthesized
Background: The search for a chemosensor that can detect Cu2+ is very long owing to the fact that an optimum level of
Cu2+ is required for human health and the recommended amount of Cu2+ in drinking water is set to be 1-2 mgL-1
. Thus, it
is very important to detect Cu2+ even at a very low concentration to assess the associated health risks.
Objective: We are still seeking for the easiest, cheapest, fastest and greenest sensor that can selectively, sensitively and
accurately detect Cu2+ with lowest detection limit. Our objective of this work is to find one such Cu2+ sensor.
Methods: We have synthesized a quinoline derivative following very easy synthetic procedures and characterize the
compound by standard methods. For sensing study, we used steady state absorption and emission spectroscopy.
Results: Our sensor can detect Cu2+ selectively and sensitively in aqueous solution instantaneously even in the presence of
excess amount of other salts. The pale-yellow color of the sensor turns red on the addition of Cu2+
. There is no
interference from other cations and anions. A 2:1 binding mechanism of the ligand with Cu2+ is proposed using Jobs plot
with binding constant in the order of 109 M-2
. We calculated the LOD to be 18 ppb, which is quite low than what is
permissible in drinking water.
Conclusion: We developed a new quinoline based chemo-sensor following straightforward synthetic procedure from very
cheap starting materials that can detect Cu2+ visually and instantaneously in aqueous solution with ppb level sensitivity
and zero interference from other ions.