Graphene-Oxide-Based FRET Platform for Sensing Xenogeneic Collagen Coassembly

Xenogeneic collagen coassembly (XCCA) offers a new view for the design and performance regulation of novel collagen-based biomaterials. But there is still a lack of accurate and sensitive method for monitoring XCCA. In this study, a simple and efficient graphene-oxide (GO)-based fluorescence resonance energy transfer (FRET) platform has been developed to sense XCCA. We first designed a fluorescein isothiocyanate (FITC)-labeled porcine skin collagen (PSC) that adsorbed on the GO surface and effectively quenched its fluorescence. Upon the addition of grass carp skin collagen (GCSC), the XCCA between PSC and GCSC resulted in desorption of FITC-PSC from GO surface and thus caused an increase in fluorescence signal. Under the optimal conditions, the fluorescence signal linearly increased with the increase in the GCSC concentration in the range of 50-1000 μg/mL, with a sensitivity of 22 μg/mL (S/N = 3). Furthermore, the developed strategy also exhibited excellent specificity and anti-interference ability. More interestingly, the thermal stability of collagen fibrils formed by XCCA is linearly related to the GCSC concentration. These results open a facile, effective, and sensitive approach for sensing XCCA and provide a new strategy for arbitrarily regulating the thermal stability of collagen fibrils.