Oxidative stress is a critical process in biological systems, involved in both normal and pathological functions; thus it is a commonly measured endpoint. Current methods for measuring oxidative stress are affected by artifacts, such as auto-oxidation. We are developing a new measurement approach based on the aggregation of functionalized gold NP in the presence of reactive oxygen species.
Optical absorption of functionalized gold NP at 520 nm (disaggregated) and 620 nm (aggregated), as measured by photoacoustic spectroscopy. Introduction of FeCl3 (an oxidizer) causes the NP to aggregate, increasing the signal at 620 nm.