Zusammenfassung
A dipstick and a sensor microtiterplate were developed for fast determination of Cu(II) in drinking water with good sensitivity. The dipsticks are based on filter paper that contains a chromogenic probe (cuprizone) along with a red fluorescent dye (sulforhodamine 101) incorporated inside a hydrogel. Upon reaction with Cu(II), the visible color of the spots shifts from pink over blue to green. ...
Zusammenfassung
A dipstick and a sensor microtiterplate were developed for fast determination of Cu(II) in drinking water with good sensitivity. The dipsticks are based on filter paper that contains a chromogenic probe (cuprizone) along with a red fluorescent dye (sulforhodamine 101) incorporated inside a hydrogel. Upon reaction with Cu(II), the visible color of the spots shifts from pink over blue to green. This enables determination of the WHO threshold level of Cu(II) in drinking water by eye-vision or using the reflectometric RGB readout of digital images of the dipsticks. Visually, 1-2000.0 mu g L-1 of Cu(II) can be determined and 1-1000.0 mu g L-1 from the evaluation of the digital images. The sensor microtiterplate was fabricated by fixing the sensor cocktail of the dipsticks on the bottom of the wells of a standard microtiterplate. Luminescence determination of Cu(II) in the microtiterplate is based on the inner-filter effect (increasing absorbance) of the Cu-cuprizone complex on the emission of sulforhodamine 101. Hence, the rhodamine emission is increasingly quenched with increasing concentrations of Cu (II). The calibration plot for quantitation of Cu(II) by utilizing a microtiterplate reader spans over more than 3 orders of magnitude from 0.1 to 300.0 mu g L-1. The limit of detection is 0.1 mu g L-1 which is the lowest for sensor microplates for determination of Cu(II) so far. The method is hardly affected in a pH range from 4.0 to 7.0 and only 5 min of incubation time are required. The selectivity for Cu(II) is high, even in presence of various heavy metals. The dipsticks and the sensor microtiterplate were successfully applied to real samples and the accuracy of both tools was validated by ICP-atomic emission spectrometry.
Altmetric