DNA tetrahedron-Au NPs-GO for enhanced fluorescence detection of serotonin

Evidence had accumulated that serotonin (5-HT), a hormone and neurotransmitter, was not only involved in a variety of different physiological and central nervous system functions but also in the development and manifestation of psychiatric diseases. Here, DNA tetrahedron-Au NPs-GO for enhanced fluorescence sensor was designed for detecting serotonin. Au NPs-GO was used as a fluorescence quencher, while fluorophore-labeled DNA tetrahedron was used as a donor, resulting in fluorescence resonance energy transfer (FRET) from the fluorophore to Au NPs-GO (signal off). With the strong binding ability of aptamer to serotonin, S5 was released from Aptamer: S5 duplex, then reacted with the tail of DNA tetrahedron (DTNs), followed by the formation of three double stranded DNA products in the tail of DTNs, bringing in signal readout responses (signal on). Consequently, a reliable, sensitive and selective sensor was obtained for one-step quantificative detection of serotonin from 50 pM to 200 nM with a detection limit of 16.8 pM. Furthermore, satisfactory stability, reproducibility, specificity and good recovery efficiency in human serum samples revealed that the proposed sensor could be served as a prospective tool for serotonin detection.