Great effort has been made in exploring techniques and catalysts for O2•− production but they always work efficiently in either acidic or base environment. Presented here is the design of a unique oxidase mimic catalyst comprising self‐assembled hemin molecules on graphdiyne (hemin/GDY) for efficient O2•− generation in wide pH ranges. Hemin molecules anchor uniformly across the carbon frame of GDY to enable atomic distribution of the active metal sites, delivering a O2•− production rate of 35.7 and 2.3 times than that of hemin and hemin/graphene, respectively. In particular, hemin/GDY can efficiently produce O2•− in acidic, alkaline, and neutral environments, delivering a wide pH behavior. Its oxidase mimic ability is demonstrated for sensing glutathione molecules in cell assays, exhibiting high selectivity, long linear range. This work opens a promising design strategy toward efficient oxidase mimic catalysts for various applications.
Instability of 2D phosphorene material is the major obstacle for its broad applications. Herein phosphorene is sandwiched with self-assembled iron porphyrin monolayers on both sides (I-Phene) to significantly enhance stability. Iron porphyrin has strong interaction with phosphorene through formation of P-Fe bonds. The sandwich structure offers excellent stability of phosphorene by both-sided monolayer protections for an intact phosphorene structure more than 40 days under ambient conditions. Meanwhile, the electron transfer between iron porphyrin and phosphorene result in a high oxidation state of Fe, making I-Phene biomimetic sensitivity toward oxidation of nitric oxide (NO) for 2.5 and 4.0 times higher than phosphorene and iron-porphyrin alone, respectively. Moreover, I-Phene exhibits excellent selectivity, a wide detection range, and a low detection limit at a low oxidation potential of 0.82 V, which is comparable with the reported noble metal based biomimetic sensors while ranking the best among all non-noble biomimetic ones. I-Phene is further used for real-time monitoring NO released from cells. This work provides effective approach against phosphorene degrading for outstanding stability, which has universal significance for its various important applications, and holds a great promise for a highly sensitive biomimetic sensor in live-cell assays.
We present sub‐ppt level detection of explosive trinitrotoluene by constructing a fast‐response electrochemical sensor using nitrogenized porous carbon spheres (NPCS). NPCS with nitrogen doping and amino functionalization accelerates charge transfer and trinitrotoluene accumulation. A high sensitivity of 60.2 μA cm−2 ppb−1 and a detection limit of 0.15 ppb are achieved on NPCS, among the best of recently reported trinitrotoluene electrochemical sensors. Moreover, response time of NPCS is greatly reduced by two times comparing with nitrogen‐free sample. NPCS also offers high selectivity, repeatability and stability, rendering new opportunities to fast detect trinitrotoluene for home security and environment protection.
Graphdiyne (GDY), an emerging type of carbon allotropes with unique sp−sp2 carbon atoms, is firstly explored for high selectivity direct electrochemical sensing of ultra‐trace level copper ions (Cu2+). It achieves a wide detection range of 0.25–380 μM and a trace level as low as 8 nM, among the best performance of reported carbon‐based sensors. It is found that GDY with unique C≡C possesses both chelating and reducing abilities to efficiently anchor and reduce Cu2+ to Cu+, eventually leading to ultrasensitive detection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.