A photoelectrochemical aptasensor based on a 3D flower-like TiO2-MoS2-gold nanoparticle heterostructure for detection of kanamycin

• Published in: Biosensors & bioelectronics Vol. 112; pp. 193 - 201
• Main Authors: Liu, Xiaoqiang, Liu, Peipei, Tang, Yunfei, Yang, Liwei, Li, Lele, Qi, Zhichong, Li, Deliang, Wong, Danny K.Y.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.07.2018
• Subjects: aptasensors; electric current; electron transfer; kanamycin; Kanamycin detection; nanogold; nanoparticles; oligonucleotides; Photoelectrochemical aptasensor; surface plasmon resonance; TiO2-MoS2-AuNP composite; Visible light excitation; Visible light excitation; TiO2-MoS2-AuNP composite; Photoelectrochemical aptasensor; Kanamycin detection
• ISSN: 0956-5663; 1873-4235; 1873-4235
• DOI: 10.1016/j.bios.2018.04.041

In this work, a sensitive photoelectrochemical aptasensor was developed for kanamycin detection using an enhanced photocurrent response strategy, which is based on the surface plasmon resonance effect of gold nanoparticles deposited on a 3D TiO2-MoS2 flower-like heterostructure. A significant aspect of this development lies in the photoelectrochemical and morphological features of the unique ternary composite, which have contributed to the excellent performance of the sensor. To develop an aptasensor, mercapto-group modified aptamers were immobilised on the photoactive composite as a recognition unit for kanamycin. The TiO2-MoS2-AuNP composite was demonstrated to accelerate the electron transfer, increase the loading of aptamers and improve the visible light excitation of the sensor. Under optimal conditions, the aptasensor exhibited a dynamic range from 0.2 nM to 450 nM of kanamycin with a detection limit of 0.05 nM. Overall, we have successfully synergised both the electrical and the optical merits from individual components to form a ternary composite, which was then demonstrated as an effective scaffold for the development of PEC biosensors. •A photoelectrochemical biosensor consisting of a TiO2-MoS2-gold nanoparticle nanocomposite is excitable by visible light.•The nanocomposite demonstrates a large surface area and high conductivity.•A kanamycin photoelectrochemical aptasensor is developed based on the nanocomposite.•Sensitive kanamycin detection was achieved using an enhanced photocurrent response strategy.