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.

Electrochemical detection of carcinoembryonic antigen based on silver nanocluster/horseradish peroxidase nanocomposite as signal probe

“…As the clinical required diagnostic level for normal CEA concentration is around 5 ng mL À1 [29], the serum samples can be diluted appropriately before test to minimize matrix effect. Compared with the values obtained by commercial ELISA kit, the detection results by the immunosensor show an acceptable agreement, with relative errors less than 9.86% (Table 2).…”

Ag nanoclusters could efficiently quench the photoresponse of CdS quantum dots for novel energy transfer-based photoelectrochemical bioanalysis

“…Among various efforts, exciton-plasmon interactions (EPI) between the noble metal nanoparticles (NPs) and quantum dots (QDs) have been demonstrated as a unique route for ingenious PEC biosensing purposes , Zhao et al, 2012. Such interesting mechanism was then used for tentative bioanalysis with a simple DNA hybridization model, which provided a feasible basis for elegant PEC bioassays and many recent protocols were proposed for addressing different targets (Zeng et al, 2013;Ma et al, 2016). Despite the progress manifested in these works, the study in this field is still in its inception phase.…”

An enhanced photoelectrochemical immunosensing platform: Supramolecular donor–acceptor arrays by assembly of porphyrin and C 60

“…As a newly developed analytical method for the detection of biomolecules, photoelectrochemical (PEC) immunosensing has become an attractive and promising analytical method (Zhang et al, 2014;Zeng et al, 2013). In the case of PEC detection process, light is used to excite active species on the electrode, and current is used as the detection signal, which is just the reverse process of electrochemiluminescence (Li et al, 2013;Zhao et al, 2014).…”