Gold nanoparticles conjugated dopamine as sensing platform for SERS detection.

In this work, the properties of dopamine and dopamine-quinone on gold nanoparticles (Au NPs) surface were studied by the constructed Au NPs/dopamine sensing platform using surface enhanced Raman scattering (SERS) spectroscopy. Interestingly, the Au NPs/dopamine-quinone exhibited the characteristic Raman band at 1270, 1335 and 1480 cm(-1) at pH 10.0, whereas, no obvious Raman band of Au NPs/dopamine was observed at pH = 6.0. Also, dopamine-quinone could be reduced by glutathione (GSH) and dopamine could be oxidized easily by superoxide radical anion (O2(-)), thus, this sensing platform could be used to determine the concentration of GSH and O2(-) in a wide range. Importantly, the utility of Au NPs/dopamine platform was demonstrated in living HeLa and normal human liver (HL-7702) cells, and responded to the concentration changes of reactive oxygen species (ROS) in real time.