ABSTRACT
OBJECTIVE: To study the effect of gold nanocage cage on the activation of reactive oxygen species (ROS) by photothermal inducing hydrogen peroxide (H2O2) in near infrared, and to analyze the relationship between ROS type and its yield and H2O2 concentration. To provide the experimental basis for the application of gold nanocage in the field of biomedicine and photothermal therapy. METHODS: The mixed solution of different concentrations of H2O2 with gold nanocage was irradiated by the equal power 808 nm near infrared laser, and the type and content of ROS produced in the different mixed solutions were detected by microprate reader and ROS fluorescent probe. RESULTS: Because of surface plasmon resonance (SPR), gold nanocage can not only produce overheating effect, but also induce H2O2 to generate more ROS (mainly single-phase oxygen and hydroxyl radicals, the content of them increases with the increase of H2O2 concentration) under the near infrared excitation. CONCLUSION: Gold nanocage can induce H2O2 to generate ROS such as single-phase oxygen and hydroxyl radicals under the near infrared excitation, and the relationship is positively correlated between the content of ROS and H2O2 concentration.
ABSTRACT
A label-free electrochemical immunosensor using hollow structure nanomaterials based on its ordered porous and big surface area was designed. Au nanocage, with good conductivity, catalysis, and biocompatibility, was prepared and modified on the surface of glassy carbon electrode with graphene to immobilize antibody of microcystin directly. In the absence of microcystin, biosensor can obtain high current response signal of electrochemical probe ( [ Fe( CN) 6 ] 3-/4-. When microcystin was combined with its antibody specifically, the charge density and mass transfer resistance on the surface of electrode increased, resulting in a decrease of the corresponding peak current of [ Fe ( CN ) 6 ] 3-/4-. This change was in proportion to the concentration of microcystin indirectly. Experiment conditions such as cultivation time of antigen and concentration of antibody were optimized. The results showed wide linear range of 0. 05 μg/L-1. 0 mg/L and the detection limit of 0. 017 ng/mL. This sensor has good stability and simple production procedure. This sensor provides a new and simple means for the ultrasensitive determination of microcystins in real water samples.