Alireza Dehghani,a Sara M. Ardekania Mahbub Hassan,a and Vincent G. Gomes∗a


The University of Sydney, Sydney, Australia


Biocompatible and photostable fluorescent probes are crucial yet challenging to develop for visualizing and tracking biological functions and interactions that occur in living organisms. We synthesized biocompatible CQDs with high quantum yield and tested them for simultaneous cellular and scaffold imaging at variable tissue depths. The CQDs, synthesized from collagen under controlled and benign conditions in a hydrothermal reactor, were characterized for their key physicochemical properties. The fluorescence characteristics were determined using two-photon microscopy and based on our results we propose a mechanism for CQD luminescence by combining the carbogenic core and edge-effect contributions to the PL behavior. The bioimaging of cells embedded in a luminescent 3D printed scaffold showed that CQDs enable imaging at depths of about 1500 μm under biomimetic conditions. Real-time videography and cell viability tests showed differential visualization of individual cells and scaffold. The excellent photostability and non-photobleaching characteristics of CQDs make them suitable for long-term whole cell and tissue imaging via multi-photon microscopy.


Presenting author biography:

Alireza Dehghani received his BS in polymer engineering in 2008 and MS from University Technology Malaysia (Malaysia) in 2011.   He is currently a 2nd-year Ph.D. student in Prof. Vincent Gomes’s group at The University of Sydney (Australia). His main research focus is on the synthesis of metal-free quantum dots and their applications for bioimaging and sensing