Ultrathin Phthalocyanine-Conjugated Polymer Nanosheet-Based Electrochemical Platform for Accurately Detecting HO in Real Time.

As a vital biological mediator and a widely used industrial oxidant, the accurate detection of hydrogen peroxide (HO) is of significance for both academic purpose and practical applications. Herein, we report a novel approach for the development of a high-performance electrochemical HO sensor constructed by iron phthalocyanine (FePc)-based diyne-linked conjugated polymeric nanosheets (NSs), FePc-CP NSs. The FePc-CP NSs were delaminated from the bulk material via a defect- and disorder-induced synthetic strategy. By the quasi-Langmuir-Shäfer method, the prepared FePc-CP NSs were self-assembled into multilayer films with controllable thickness on electrodes. Owing to the highly exposed active centers on the surfaces, the FePc-CP NS film-modified electrodes exhibited excellent HO determination performance with a wide linear detection range (0.1-1000 μM), a short response time (the response current approached the maximum value within 0.1 s), a low limit of detection (0.017 μM), and excellent sensitivity (97 μA cm mM), which are comparable to the best results reported so far for electrochemical HO sensors. In addition, the fabricated electrochemical HO sensor also displayed satisfactory stability, reproducibility, and selectivity. Furthermore, the obtained FePc-CP NS film sensor can be applied in real-time monitoring of HO in commercial orange juice and beer as well as HO secreted from A549 live cells, revealing its application potential toward the accurate detection of HO in real-sample analysis.