Enhanced Peroxidase‐Like Performance of Gold Nanoparticles by Hot Electrons

• Published in: Chemistry : a European journal Vol. 23; no. 28; pp. 6717 - 6723
• Main Authors: Wang, Chen, Shi, Yi, Dan, Yuan‐Yuan, Nie, Xing‐Guo, Li, Jian, Xia, Xing‐Hua
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 17.05.2017
• Subjects: Biocompatible Materials - chemistry; Biocompatible Materials - metabolism; Biosensing Techniques; Biosensors; Catalysis; Chemistry; Electrons; enzyme mimics; Enzymes; Functional groups; Gold; Gold - chemistry; gold nanoparticles; Hot electrons; Hydrogen peroxide; Hydrogen Peroxide - chemistry; Kinetics; Light; localized surface plasmon resonance; Metal Nanoparticles - chemistry; Nanoparticles; Oxidants; Oxidation; Oxidizing agents; Peroxidase; Peroxidase - chemistry; Peroxidase - metabolism; reaction mechanism; Spectrophotometry; Spectroscopy; Substrates; Surface Plasmon Resonance; hot electrons; localized surface plasmon resonance; reaction mechanism; gold nanoparticles; enzyme mimics
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201605380

Enzyme mimics have been widely used as alternatives to natural enzymes. However, the catalytic performances of enzyme mimics are often decreased due to different spatial structures or absence of functional groups compared to natural enzymes. Here, we report a highly efficient enzyme‐like catalytic performance of gold nanoparticles (AuNPs) by visible‐light stimulation. The enzyme‐like reaction is evaluated by the catalytic reaction of AuNPs oxidizing a typical chromogenic substrate 3,3′,5,5′‐tetramethylbenzydine (TMB) with hydrogen peroxide as an oxidant. From investigations of the wavelength‐dependent reaction rate, radical capture, hole‐donor addition, and dark‐field scattering spectroscopy experiments, it is revealed that the strong plasmonic absorption of AuNPs facilitates generation of hot electrons, which are transfered from AuNPs to the adsorbed reactant molecule, greatly promoting the catalytic performance of the enzyme‐like catalytic reaction. The present work provides a simple method for improving the performance of enzyme mimics, which is expected to find further application in the field of plasmon‐enhanced biocatalysis and biosensors. Feelin’ hot hot hot: Upon visible‐light irradiation, strong plasmonic absorption of AuNPs facilitates formation of hot electrons on AuNPs surface. Due to energy matching, the hot electrons will inject into the H2O2 molecular orbit, cleaving H2O2 into an OH. radical, which oxidizes 3,3′,5,5′‐tetramethylbenzydine (TMB) into TMB+ rapidly, and enhances the enzyme‐like performance.