Glycosaminoglycan / gold nanocluster hybrid nanoparticles as a new sensing platform: Metastatic potential assessment of cancer cells

A novel fluorescent heparanase assay based on hybrid nano-assembly of gold nanocluster and glycosaminoglycan is developed. The nanoparticle probes are fabricated through the co-assembly of positively charged gold nanoclusters with negatively charged heparin molecules, which is accompanied by a dramatic size change and a 2.5-fold fluorescence enhancement. It is demonstrated that the fluorescence enhancement is due to denser aggregation of Au-thiolate complexes in the hybrid nanoparticle and the fluctuation of the fluorescence intensity is an indicator of the variation in assembly efficiency. Experiments in solution and in cell lysis media showed that the heparanase could turn-off the fluorescence with a high selectivity, which could be utilized for the assessment of heparanase activity and the metastatic potentials of different tumour cells. This assay technique is low cost, easy to prepare, and showing good performance. The co-assembly strategy has potential to be transferable to construct other functional nanomaterial.