Gold Nanoprobe-Enabled Three-Dimensional Ozone Imaging by Optical Coherence Tomography.

Ozone (O3) would be harmful to human skin for its strong oxidizing property, especially when stratum corneum or corneal epithelium is wounded. Imaging the penetration and distribution of ozone at depth is beneficial for studying the influence of ozone on skin or eyes. Here, we introduced a facile method for three-dimensional (3D) imaging of the penetration of O3 into the anterior chamber of an isolated crucian carp eye by using optical coherence tomography (OCT) combined with gold triangular nanoprisms (GTNPs) as the contrast agent and molecular probe. We illustrated the specific response of GTNPs to ozone and demonstrated that GTNPs can function as an efficient nanoprobe for sensing O3. The stabilities of GTNPs in different biologic solutions, as well as the signal intensity of GTNPs on an OCT imaging system, were investigated. Visualization of 3D penetration and distribution of O3 in the biologic tissue was proved for the first time. The quantitative analysis of O3 diffusion in the anterior chamber of the fish eye revealed a penetration depth of 311 μm within 172 min. Due to the strong scattering, near-infrared extinction band, and easy functionalization of GTNPs, they could further serve as nanoprobes for 3D OCT or multimodal imaging of other molecules or ions in the future.