Photoelectrochemical and electrochemical ratiometric aptasensing: A case study of streptomycin

Autor: Xiuli Shen, Dong Liu, Chengxi Zhu, Yuye Li, Yang Liu, Tianyan You
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Electrochemistry Communications, Vol 110, Iss , Pp - (2020)
Druh dokumentu: article
ISSN: 1388-2481
DOI: 10.1016/j.elecom.2019.106637
Popis: There has been much interest in constructing ratiometric sensors using different sensing techniques because of their synergistic effect, although the simultaneous collection of the signals is challenging. Herein, we propose a ratiometric aptasensing strategy based on the dual-detection model with a photoelectrochemical (PEC) “signal-on” and an electrochemical (EC) “signal-off”. As a proof-of-concept study, CdTe quantum dots (CdTe QDs) and a methylene blue-labeled aptamer (MB-Apt) were used to generate PEC and EC signals in the sensing system. The target-induced conformational change of MB-Apt pushed MB away from the electrode, thereby decreasing the EC signal; at the same time, the reduced steric hindrance favored the restoration of the PEC signal from the CdTe QDs. Thus, this PEC-EC strategy can achieve the PEC “signal-on” and EC “signal-off” states simultaneously, as well as allowing quantitative analysis of the target based on the ratio of the current intensities. As a model application, an aptasensor fabricated for streptomycin detection showed a wide linear range from 0.03 to 100 μM with a detection limit of 10 nM (S/N = 3). The proposed sensing platform displayed superior analytical properties compared with methods based on PEC or EC alone. Our work provides an efficient dual-detection model-based ratiometric strategy for advanced analysis, and paves the way to the simultaneous acquisition of signals. Keywords: Ratiometric strategy, Dual-detection model, Photoelectrochemistry, Electrochemistry, Aptasensor
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