Study on a highly selective colorimetric chemosensor for Cu2+ detection and its indirect sensing for hypochlorite

• A colorimetric chemosensor for Cu2+ detection was synthesized.
• The colorimetric chemosensor allows the “naked-eyes” detection of Cu2+.
• The colorimetric chemosensor can mimic an AND logic gate function.
• The colorimetric chemosensor can act as a potential probe towards ClO−.

A highly-selective colorimetric chemosensor (CS1) for Cu2+ detection is prepared and characterized. This Cu2+ sensor can act as a potential probe towards ClO−, by taking advantage of the oxidation property of hypochlorite and different coordinating property of Cu+ and Cu2+ with CS1. Upon addition of ClO−, the absorption maximum band of CS1 in the presence of Cu+ in CH3CN/H2O (4:1, v/v) shows a large red shift from 398 to 552 nm (Δ = 154 nm), and a visually color change from orange to purple is very easy to observe by naked-eyes, while other commonly-coexisting anions can not induce such similar changes. CS1 mimic an AND logic gate function with Cu+ and ClO− as inputs and A552 nm/A398 nm as output (A = absorbance), and this function can be easily reset by S2−.