title: Using graphene-based plasmonic nanocomposites to quench energy from quantum dots for signal-on photoelectrochemical aptasensing.
abstract: On the basis of the absorption and emission spectra overlap, an enhanced resonance energy transfer caused by excition-plasmon resonance between reduced graphene oxide (RGO)-Au nanoparticles (AuNPs) and CdTe quantum dots (QDs) was obtained. With the synergy of AuNPs and RGO as a planelike energy acceptor, it resulted in the enhancement of energy transfer between excited CdTe QDs and RGO-AuNPs nanocomposites. Upon the novel sandwichlike structure formed via DNA hybridization, the exciton produced in CdTe QDs was annihilated. A damped photocurrent was obtained, which was acted as the background signal for the development of a universal photoelectrochemical (PEC) platform. With the use of carcinoembryonic antigen (CEA) as a model which bonded to its specific aptamer and destroyed the sandwichlike structure, the energy transfer efficiency was lowered, leading to PEC response augment. Thus a signal-on PEC aptasensor was constructed. Under 470 nm irradiation at -0.05 V, the PEC aptasensor for CEA determination exhibited a linear range from 0.001 to 2.0 ng mL(-1) with a detection limit of 0.47 pg mL(-1) at a signal-to-noise ratio of 3 and was satisfactory for clinical sample detection. Since different aptamers can specifically bind to different target molecules, the designed strategy has an expansive application for the construction of versatile PEC platforms.
authors.affiliation: Jiangsu Key Laboratory of Biofunctional Materials, College of Chemistry and Materials Science, Nanjing Normal University , Nanjing 210023, P. R. China.
authors.forename: Xianxiang
authors.initials: X
authors.lastname: Zeng
authors.forename: Shishi
authors.initials: S
authors.lastname: Ma
authors.forename: Jianchun
authors.initials: J
authors.lastname: Bao
authors.forename: Wenwen
authors.initials: W
authors.lastname: Tu
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Dai
mesh_terms: D000818:Animals; D052157:Aptamers, Nucleotide / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D002272:Carcinoembryonic Antigen / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D004563:Electrochemistry; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D055668:Photochemical Processes; D045663:Quantum Dots
chemical_list: D052157:Aptamers, Nucleotide; D002272:Carcinoembryonic Antigen; D006046:Gold; D006108:Graphite