Details

Autor(en) / Beteiligte

• Qin, Xiaofei
• Wang, Qianqian
• Geng, Liping
• Shu, Xiaoli
• Wang, Yan

Titel

A “signal-on” photoelectrochemical aptasensor based on graphene quantum dots-sensitized TiO2 nanotube arrays for sensitive detection of chloramphenicol

Ist Teil von

• Talanta (Oxford), 2019-05, Vol.197, p.28-35

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2019

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• An ultrasensitive photoelectrochemical (PEC) aptasensor was designed for detection of chloramphenicol (CAP) based on graphene quantum dots-sensitized TiO2 nanotube arrays (GQDs/TiO2 NTs). The GQDs/TiO2 NTs nanohybrids were prepared by a coupling technique of linker molecule binding and electrophoretic deposition. It exhibited significantly enhanced visible-light photoelectrochemical activity, which was firstly employed as the photoactive material for fabrication of PEC aptasensor. As the recognition unit, the aptamers of CAP were immobilized on GQDs/TiO2 NTs photoelectrode via π–π stacking interaction between GQDs and the nucleobases of the aptamer. In this signal-on proposal, the aptasensor was used for the label-free analysis of CAP by monitoring the increase in photocurrent that resulted from the formation of aptamer-CAP bioaffinity complexes with ascorbic acid as an efficient electron donor for scavenging photogenerated holes. Under the optimized conditions, the aptasensor showed a wide linear range from 0.5 nM to 100 nM for CAP detection with a low detection limit of 57.9 pM (S/N = 3). With good selectivity and sensitivity, the PEC aptasensor was applied to the determination of CAP in spiked honey samples with satisfactory results, suggesting that the GQDs/TiO2 NTs photoelectrode has a promising application in constructing PEC sensor platform. A novel visible-light driven photoelectrochemical aptasensor based on graphene quantum dots-sensitized TiO2 nanotube arrays has been fabricated and used for the determination of chloramphenicol with good selectivity and high sensitivity. [Display omitted] •A “signal-on” PEC aptasensor based on GQDs/TiO2 NTs was developed.•The GQDs/TiO2 NTs nanohybrids significantly improve photocurrent response.•The aptasensor exhibits high sensitivity for chloramphenicol detection.•The proposed method can be used in food safety detection.