A novelcomposite film ofAu@carbondots(Au@CDs)–chitosan (CS)modified glassycarbonelectrode
(Au@CDs–CS/GCE) waspreparedinasimplemannerandappliedinthesensitiveandreliable
determination ofdopamine(DA).TheCDshadcarboxylgroupswithnegativecharge,whichnotonly
gaveithavegoodstabilitybutalsoenabledinteractionwithaminefunctionalgroupsinDAthrough
electrostatic interactiontomultiplyrecognizeDAwithhighspecificity,andtheAunanoparticlecould
make thesurfaceoftheelectrodemoreconductive.ComparedwiththebareGCE,CS/GCE,andCDs–CS/
GCE electrodes,theAu@CDs–CS/GCE hadhighercatalyticactivitytowardtheoxidationofDA.
Furthermore,Au@CDs–CS/GCE exhibitedgoodabilitytosuppressthebackgroundcurrentfromlarge
excessascorbicacid(AA)anduricacid(UA).Undertheoptimalconditions,selectivedetectionofDAina
linear concentrationrangeof0.01–100.0 μM wasobtainedwiththelimitof0.001 μM (3S/N).Atthesame
time, theAu@CDs–CS/GCE wasalsoappliedtothedetectionofDAcontentinDA'sinjectionwith
satisfactory results,andthebiosensorcouldkeepitsactivityforatleast2weeks.