半胱氨酸化学键合金纳米颗粒用于氧化性小分子可视化测定的载体研究
摘要
Gold nanoparticles (AuNPs) have the unique property of plasmon resonance absorption (PRA). In this contribution, universal colorimetric detection of oxidants was achieved using cysteine induced AuNPs aggregation, which leads to a red-shift of in the PRA. The SH group of a cysteine molecule can be oxidized into a –S–S– bond in the presence of oxidants such as H<sub>2</sub>O<sub>2</sub> or <sup>1</sup>O<sub>2</sub>, which leads to reduced aggregation in the AuNPs. These blue-shifts of the PRA from 740 nm to 531 nm, and results in a blue-to-red color change. It was found that the ratio of absorbance at 740 nm to that at 531 nm (<italic>A</italic><sub>740</sub>/<italic>A</italic><sub>531</sub>) was in proportion to the concentrations of H<sub>2</sub>O<sub>2</sub> and <sup>1</sup>O<sub>2</sub>. Also, this colorimetric method can be successfully applied to detecting H<sub>2</sub>O<sub>2</sub> in rat brains, which offers performance similar to flow injection-chemiluminescence.