Year: 2025
Type: article
Abstract: Fluorescent beads have wide applications in fields of biomedicine and biotechnology. Characterisation and evaluation of the multi-photon properties of fluorescent beads is essential for ensuring their effectiveness and reliability in multi-photon imaging applications. However, at the 1 700 nm excitation window which is well-suited for deep biological tissue imaging, such characterization techniques remain limited, hindering practical selection and application of fluorescent beads. In this study, a custom-built multi-photon imaging system operating at the 1 700 nm is utilized to characterize the multi-photon properties of two types of commercially available fluorescent beads: Fluosphere and polystyrene quantum dot fluorescent beads. Using multi-photon imaging, one can determine the multi-photon excitation order and relative multi-photon action cross-section of fluorescent beads, compare the multi-photon signal level, and investigate the photobleaching properties of the fluorescent beads to evaluate their photostability. Meanwhile, one can further determine the spatial resolution of the imaging system through multi-photon imaging. The results show that the relative action cross section and stability of Fluosphere are superior to those of quantum dot fluorescent beads at the 1 700 nm window. Moreover, our imaging system has a sub-micron spatial resolution. These findings provide a reference for selecting fluorescent beads in multi-photon imaging and characterizing the spatial resolution of imaging systems.
Authors: Jiemei YAN, Yingxian ZHANG, Sijia TANG, Ping QIU, Ke WANG
Institution: Shenzhen University
Language: English
Subfield: Biophysics
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W4410406160