Visual and Portable Strategy for Copper(II) Detection Based on a Strip like Poly(Thynnine)-Caged and Microwell-Printed Hydrogel

Due to its importance to develop strategies for copper(II) (Cu2+) detection, we here report a visual and portable strategy for Cu2+ detection based on designing and using a strip like hydrogel. The hydrogel is functionalized through caging poly(thymine) as probes, which can effectively template the formation of fluorescent copper nanopartides (CuNPs) in the presence of the reductant (ascorbate) and Cu2+. On the hydroger s surface, uniform wells of microliter volume (rrucrowells) are printed for sample injection When the injected sample is stained by Cu2+, fluorescent CuNPs will be in situ templated by poly T in the hydrogel. With ultraviolet (UV) irradiation, the red fluorescence of CuNPs can be observed No fluorescence Red fluorescence by naked eye and recorded by a common camera without complicated instruments Thus, the strategy integrates sample Injection, reaction and indication with fast signal response, providing an add-and-read manner for visual and portable detection of Cu2+, as well as a strip -like strategy. Detection ability with a detectable minimum concentration of 20 pM and practically applicable properties have been demonstrated, such as resistance to environmental interference and good constancy, inclicating that the strategy holds great potential and significance for popular detection of Cu2+, especially in remote regions We believe that the strip like hydrogel-based methodology is also applicable to ' other targets by virtue of altering probes.