Platinum/carbon dots nanocomposites from palm bunch hydrothermal synthesis as highly efficient peroxidase mimics for ultra-low H2O2 sensing platform through dual mode of colorimetric and fluorescent detection

Abstract

Detection of hydrogen peroxide and glucose in nanomolar level is crucial for point-of-care medical diagnosis. It has been reported that human's central nervous system diseases such as Alzheimer's disease, Parkinson's disease, and even amyotrophic lateral sclerosis, are presumably caused H₂O₂ or reactive radical species (ROS). Sensing of H₂O₂ released from human biofluids, tissues, organ from metabolism disorder at ultra-low concentration assists for early identification of severe diabetis mellitus related to glucose, and heart attack, as well as stroke related to cholesterol. In this work, carbon dots (CDs) having an average diameter at 6.99 nm with highly photoluminescence performance were successfully synthesized from palm empty fruit bunch (EFB) using green and environmentally friendly process via hydrothermal condition. CDs acted well on peroxidase-like activity for H₂O₂ detection at room temperature, however their sensitivity on ultra-low H₂O₂ concentration needed to be improved. To enhance their reactivity on H₂O₂ nanozyme activity at room temperature, synthesis of hybrid metal nanoparticles (AgNPs and PtNPs) on CDs surface was established. The findings exhibited that CDs/PtNPs was the most suitable nanozyme achieving highly efficient peroxidase mimic for dual mode of colorimetric and fluorescent H₂O₂ sensing platform at very low limit of detection of 0.01 mM (10 nM) H₂O₂.

Keywords: Colorimetry and fluorimetry peroxide sensing; Horseradish peroxidase mimetic; Hydrothermal carbon dots synthesis; Silver/carbon dots and platinum/carbon dots nanocomposite.