Sensitive and selective turn off-on fluorescence detection of heparin based on the energy transfer platform using the BSA-stabilized Au nanoclusters/amino-functionalized graphene oxide hybrids

An ultra-sensitive and selective turn off-on fluorescence detection of heparin based on the energy transfer in the BSA-stabilized gold nanoclusters/amino-functionalized graphene oxide (BSA-AuNCs/NH 2 -GO) hybrids was successfully realized. The BSA-AuNCs containing amounts of carboxyl groups could be absorbed on the surface of NH 2 -GO through the electrostatic interaction , which resulted in the fluorescence quenching of BSA-AuNCs with high efficiency. However, heparin, possessing high density of negative charge, could compete with BSA-AuNCs to bind NH 2 -GO and block the energy transfer from BSA-AuNCs to NH 2 -GO. The fluorescence recovery of BSA-AuNCs was closely related to the amount of heparin and there was a good linear relationship between fluorescence recovery of BSA-AuNCs and heparin over the range of 100   ng/mL to 30   μg/mL with a detection limit of 40   ng/mL. What's more, the fluorescence assay was successfully applied for heparin sensing in human serums and intracellular imaging.