Discriminative spatial localisation in confocal reflectance and carbon dots-based fluorescence imaging using mixed-mode endoscopic scanner

• Main Authors: Leong Y.S., Mokhtar M.H.H., Ahmad Nazri N.A., Abu Bakar M.H., Zan M.S.D., Arsad N., Abdul P.M., A. Bakar A.A.
• Other Authors: 57202929965
• Format: Article
• Published: Taylor and Francis Ltd. 2025
• Subjects: Nanocantilevers; Polymer films; Reflection; Semiconducting films; Single mode fibers; Carbon dots; Confocal reflectance; Endoscopic scanner; Fluorescence imaging; Fluorescence signals; Lissajous; Lissajous scanning; Mixed mode; Single fiber; Spatial localization

Carbon dots (CDs)-based fluorescence imaging with confocal reflectance effectively localises labelled structures with clear sample visualization. Yet, integrating these modalities into single-fibre cantilever-based endoscopic scanners poses challenges. Thus, we present an endoscopic scanner with a mixed-mode fibre cantilever for dual modalities imaging. The cantilever features two-attached fibre construction for multiple illumination and detection channels without additional optical components. The measured lateral and axial resolutions are 5.81 and 6.52 �m, respectively with field-of-view of 408 ? 488 �m. The fluorescence detection capability was first verified using fluorescent microspheres and CD-embedded polymer film, followed by confocal reflectance and CDs-based fluorescence imaging on labelled fibrous network and plant samples. The results demonstrate the complementary strengths of confocal reflectance, which extracts surface profiles, and CDs-based fluorescence, which captures fluorescence signals, leading to precise localization of fluorescence signals within the sample. Switching modality schemes at the scanner?s back-end enables implementation of different modalities. ? 2024 The Author(s). Published with license by Taylor & Francis Group, LLC.