Dopamine (DA), am omentousc atecholamine which belongs to the family of excitatory chemical neurotransmitters,i sw idely distributed in the mammalian centraln erve system [1].N umerousd isorders would emerge once altered the level of DA in human body,t herefore,i ti ss ignificantt of ind sensitive and selective methodst od etect DA for the diagnostics of neurological diseases.Electrochemiluminescence( ECL) is az ero background analytical detectiont echnique due to the ability of access to exciteds tates of molecules withouta na dditional photo-excitation source but with the control of electrochemistry [2].I nt he past decades,m any luminescence systems, such as Ru(bpy) 3 2 + -t ripropylamine (TPA), luminol-H 2 O 2 [3] and QDs-S 2 O 8 2À [4],h ave been widely investigateda nd applied in chemical analysis.N evertheless,t he ECL of dissolved oxygen was always ignored as backgrounde mission in above systems.K umarf irstly proved that the background emission at 630 nm in Ru(bpy) 3 2 + -TPAs ystem originate from the dimeric 1 D g state of dissolved oxygen during the electrochemical oxidation of TPA [ 5].A nd the anodic ECL from dissolved oxygen has been greatly improved and successfully usedt od etect glucoseo xidase by using 2-(dibutylamino) ethanol (DBAE) asc o-reactant by our group [6].H owever, the ECL intensity of dissolvedo xygen is still very limited.In this work, TiO 2 /Pt electrode was fabricated by dropping TiO 2 NPs dispersion ontot he whole platinume lectrode surface directly.C ompared with the bare Pt electrode,t he ECL intensity of O 2 + DBAE system could be enlarged by ca. 3-fold at TiO 2 /Pt electrode.T he enhanced ECL mechanism was investigated by cyclic voltammetry. Furthermore,inthe anodic potential scan, DA can be oxidized to produce o-benzoquinone species,w hich could quench the excited state of dissolved oxygen effectively [7].M oreover, the adsorption of DA on TiO 2 NPs surface form af ive membered ring coordination complex to block the active sites of TiO 2 NPs [8],w hich could also facilitatet he quenching effect. Consequently,ahigh sensitive and selective ECL sensor for the determination of DA has been established. Thed iagrammatic presentation of detecting DA by this ECL senor is shown in Scheme1.Abstract:T he anodic electrochemiluminescence (ECL)o f dissolved oxygen with 2-(dibutylamino)e thanol (DBAE) on platinum electrode has been reported previously by our group. Interestingly,t he ECL intensity can be greatly amplified at TiO 2 nanoparticles modified platinum electrode (TiO 2 /Pt), whichi sd ue to the catalytic effect of TiO 2 nanoparticles to electrochemical oxidation of DBAE. It is the first case to obtain the enhanced ECL froml uminophor by electrochemical catalysis of co-reactant. Thee nhanced anodic ECL intensity can be quenched by dopamine sensitively.A nd the ECL intensity versus the logarithm of concentration of dopaminew as linear over the 4.0 10 À12 -1.8 10 À8 M( R 2 = 0.9957),w ith the limit of detection of 2.7 10 À12 M(S/N = 3).