A hydrogel based zinc(II) sensor for use in fluorescent multi-well plate analysis

A polymeric hydrogel containing a photoinduced electron transfer (PET) based probe for Zn(II) has been formulated into the wells of a 96-well plate. Upon addition of Zn(II) ions to selected wells, the fluorescence of the gel was observed to increase in a concentration dependent manner in the 0.25–1.75 mM range. The millimolar binding constant observed for this probe is higher than that reported for other Zn(II) probes in the literature and offers the possibility to determine the concentration of this ion in environments where the Zn(II) concentration is high. The combination of the multi-well plate set-up with fluorescence detection offers the possibility of high-throughput screening using low sample volumes in a timely manner. To the best of our knowledge, this is the first reported example of a polymeric hydrogel sensor for zinc with capability for use in fluorescence multi-well plate assay.