Fig. 2
A DPV analysis of the designed aptasensor: bare GCE (a), Au@CuCl2 NW-modified GCE (b), PdCuB MNS-modified GCE (c), PdCuB MNs nanotag-based biosensor without target exosomes (d), PdCuB MNs without PD-L1 aptamer-based biosensor (e) and PdCuB MNs nanotag-based biosensor with target exosomes (f). DPV measurements were executed in 0.01 M PBS (pH 7.4) with 5 mM H2O2 in a potential range of 0.15 ~ − 0.65 V. B Signal transduction process of electrochemical exosome aptasensor. EIS C and CV D characterization of bare GCE (a), Au@CuCl2 NWs/GCE (b), CD63 Apt./Au@CuCl2 NWs/GCE (c), exosomes/CD63 Apt./Au@CuCl2 NWs/GCE (d). In the EIS measurements, the frequency range was 0.02 Hz ~ 100 kHz, the amplitude was 5 mV, and the CV measurements ranged from − 0.2 V to 0.6 V vs. Ag/AgCl reference at 0.15 V/s