Inkjet-printed disposable metal complexing indicator-displacement assay for sulphide determination in water

A sulphide selective colorimetric metal complexing indicator-displacement assay has been developed using an immobilized copper(II) complex of the azo dye 1-(2-pyridylazo)-2-naphthol printed by inkjetting on a nylon support. The change in colour measured from the image of the disposable membrane acquired by a digital camera using the H coordinate of the HSV colour space as the analytical parameter is able to sense sulphide in aqueous solution at pH 7.4 with a dynamic range up to 145 mu M, a detection limit of 0.10 mu m and a precision between 2 and 11%. (C) 2015 Elsevier B.V. All rights reserved.