title: Visible light photoelectrochemical sensor for ultrasensitive determination of dopamine based on synergistic effect of graphene quantum dots and TiO2 nanoparticles.
abstract: We have demonstrated a facile approach for fabricating graphene quantum dots-TiO2 (GQDs-TiO2) nanocomposites by a simple physical adsorption method. Compared with pure GQDs and TiO2 nanoparticles (NPs), the as-prepared GQDs-TiO2 nanocomposites showed enhanced photoelectrochemical (PEC) signal under visible-light irradiation. The photocurrent of GQDs-TiO2/GCE was nearly 30-fold and 12-fold enhancement than that of GQDs/GCE and TiO2/GCE, respectively, which was attributed to the synergistic amplification between TiO2 NPs and GQDs. More interestingly, the photocurrent of GQDs-TiO2 nanocomposites was selectively sensitized by dopamine (DA), and enhanced with the increasing of DA concentration. Further, a new PEC methodology for ultrasensitive determination of DA was developed, which showed linearly enhanced photocurrent by increasing the DA concentration from 0.02 to 105 μM with a detection limit of 6.7 nM (S/N=3) under optimized conditions. This strategy opens up a new avenue for the application of GQDs-based nanocomposites in the field of PEC sensing and monitoring.
authors.affiliation: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors.forename: Yuting
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors.forename: Xiaojiao
authors.initials: X
authors.lastname: Du
authors.affiliation: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors.forename: Jing
authors.initials: J
authors.lastname: Qian
authors.affiliation: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors.forename: Hanping
authors.initials: H
authors.lastname: Mao
authors.affiliation: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: wangkun@ujs.edu.cn.
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
mesh_terms: D004298:Dopamine / Q000032:analysis*; D055664:Electrochemical Techniques; D006108:Graphite / Q000737:chemistry*; D008027:Light; D053768:Metal Nanoparticles / Q000737:chemistry*; D010084:Oxidation-Reduction; D045663:Quantum Dots / Q000737:chemistry; D014025:Titanium / Q000737:chemistry
chemical_list: C009495:titanium dioxide; D006108:Graphite; D014025:Titanium; D004298:Dopamine
keywords: Dopamine; Graphene quantum dot; Photoelectrochemical sensor; Synergistic effect; TiO(2) nanoparticle