2D transition metal carbide MXene as a robust biosensing platform for enzyme immobilization and ultrasensitive detection of phenol

Publication date: 1 June 2018
Source:Biosensors and Bioelectronics, Volume 107
Author(s): Lingxia Wu, Xianbo Lu, Dhanjai, Zhong-Shuai Wu, Yanfeng Dong, Xiaohui Wang, Shuanghao Zheng, Jiping Chen
MXene-Ti3C2, as a new class of two-dimensional (2D) transition metal carbides (or nitrides), has been synthesized by exfoliating pristine Ti3AlC2 phases with hydrofluoric acid. The SEM and XRD images show that the resultant MXene possesses a graphene-like 2D nanostructure. and the surface of MXene has been partially terminated with -OH, thus providing a favorable microenvironment for enzyme immobilization and retaining their bioactivity and stability. Considering the unique metallic conductivity, biocompatibility and good dispersion in aqueous phase, the as-prepared MXene was explored as a new matrix to immobilize tyrosinase (a model enzyme) for fabricating a mediator-free biosensor for ultrasensitive and rapid detection of phenol. The varying electrochemical measurements were used to investigate the electrochemical performance of MXene-based tyrosinase biosensors. The results revealed that the direct electron transfer between tyrosinase and electrode could be easily achieved via a surface-controlled electrochemical process. The fabricated MXene-based tyrosinase biosensors exhibited good analytical performance over a wide linear range from 0.05 to 15.5 μmol L⁻¹, with a low detection limit of 12 nmol L⁻¹ and a sensitivity of 414.4 mA M⁻¹. The proposed biosensing approach also demonstrated good repeatability, reproducibility, long-term stability and high recovery for phenol detection in real water samples. With those excellent performances, MXene with graphene-like structure is proved to be a robust and versatile electrochemical biosensing platform for enzyme-based biosensors and biocatalysis, and has wide potential applications in biomedical detection and environmental analysis.



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