Boosting Photo-Electro-Fenton Process Via Atomically Dispersed Iron Sites on Graphdiyne for InVitro Hydrogen Peroxide Detection

Hydrogen peroxide (H2O2) is essential in oxidative stress and signal regulation of organs of animal body. Realizing in vitro quantification of H2O2 released from organs is significant, but faces challenges due to short lifetime of H2O2 and complex bio-environment. Herein, rationally designed and constructed a photoelectrochemical (PEC) sensor for in vitro sensing of H2O2, in which atomically dispersed iron active sites (Hemin) modified graphdiyne (Fe-GDY) serves as photoelectrode and catalyzes photo-electro-Fenton process. Sensitivity of Fe-GDY electrode is enhanced 8 times under illumination compared with dark condition. The PEC H2O2 sensor under illumination delivers a wide linear range from 0.1 to 48 160 mu m and a low detection limit of 33 nm, while demonstrating excellent selectivity and stability. The high performance of Fe-GDY is attributed to, first, energy levels matching of GDY and Hemin that effectively promotes the injection of photo-generated electrons from GDY to Fe3+ for reduced Fe2+, which facilitates the Fe3+/Fe2+ cycle. Second, the Fe2+ actively catalyzes H2O2 to OH- through the Fenton process, thereby improving the sensitivity. The PEC sensor demonstrates in vitro quantification of H2O2 released from different organs, providing a promising approach for molecular sensing and disease diagnosis in organ levels.

Automated summary

A photoelectrochemical sensor (PEC) was designed and constructed for in vitro detection of H2O2 using atomically dispersed iron active sites (Hemin) modified graphdiyne (Fe-GDY) as the photoelectrode. The sensor exhibits high sensitivity, selectivity, and stability, and can quantify H2O2 released from different organs within a linear range of 0.1 to 48,160 μm. This PEC sensor provides a promising approach for molecular sensing and disease diagnosis at the organ level.