Highly selective sensing of hydrogen peroxide based on cobalt-ethylenediaminetetraacetate complex intercalated layered double hydroxide-enhanced luminol chemiluminescence

In this study, Co(II)-EDTA-intercalated Mg-Al layered double hydroxides (LDHs) synthesized by anion exchange method were immobilized in a clear quartz tube to fabricate a novel chemiluminescence (CL) flow-through sensor. Interestingly, this simple micro-fabricated flow cell could greatly enhance the CL signals from the luminol-H2O2 reaction. The detection limit for H2O2 (S/N = 3) was 0.14 μM. Trace metal ions in the matrix had no effect because they were easy to complex with EDTA. The proposed sensor has been successfully applied to determine H2O2 in snow water samples with simple procedures, shorter response time and higher selectivity. The results demonstrated that this proposed method had great potential in chemical/biological sensing for H2O2 as well as for other oxidase-based reactions producing H2O2. To the best of our knowledge, this is the first report on the use of metal complex-intercalated LDHs for CL signal amplification.