Fig. 1From: Surface plasmon resonance biosensor for exosome detection based on reformative tyramine signal amplification activated by molecular aptamer beaconCharacterization of the signal amplifier of AuNPs-Ty. A TEM image of AuNPs. Scale bars = 100 nm, B UV–vis absorption spectra of AuNPs (black line) and AuNPs-Ty (red line)Back to article page