▎ 摘　　要

The enzyme cleaving the beta-site amyloid precursor protein (BACE1) is a prime therapeutic target for treatment of Alzheimer's disease (AD). Hence, improved high-throughput methods for probing the activity of BACE1 are crucial with respect to the discovery of novel drugs for treatment and prevention of AD. We describe a graphene oxide (GO)-based fluorescent platform for the determination of BACE1 activity and screening of its inhibitors. It is found that covalent linkage of the fluorescein isothiocyanate (FITC)-labeled enzyme substrate (of sequence GTEEISEVNLDAEFRHDSGYKK) to GO results in quenching of the FITC fluorescence, but that on peptide cleavage by BACE1, FITC is released from the GO surface and fluorescence is restored. In contrast to other fluorescent assays, the method presented here shows much higher quenching efficiency and sensitivity, and it can be used at pH value of 4.5 where BACE1 exhibits higher activity. The inhibition of BACE1 activity by a potential inhibitor results in retarded fluorescence recovery. The half-maximum inhibition value of a well-known BACE1 inhibitor was found to be 82.7 nM, which is in agreement with the value reported earlier. In our perception, this method represents a valuable tool for screening of BACE1 inhibitors and discovery of AD drugs in a high-throughput screening format using microplate readers.