Recent advance in biosensing applications based on two-dimensional transition metal oxide nanomaterials

In recent years, two-dimensional transition metal oxide nanomaterials (2D TMONs) have drawn increasing attention due to their various functionalization, tunable electronic characteristics, unique optical properties, excellent chemical and thermal stabilities, large surface area and strong oxidation ability. The metal ions of 2D TMONs usually possessed the unfilled d-orbital. Furthermore, 2D TMONs contained oxygen ion in comparison with other 2D nanomaterials. Thus, 2D TMONs has a series of features which included reactive electronic transitions, high dielectric constants, wide bandgaps and excellent electrical property. They could act as quencher to quench the fluorescence intensity of fluorescent sensor or electrochemiluminescence. Recently, they have been demonstrated both excellent biological compatibility and good dispersion for the oxygen ions. These properties endow 2D TMONs could be used in optic, electronic, catalytic, energy technology, biosensing to biomedical diagnosis and therapy. In this review, we provide a brief overview regarding the progress of 2D TMONs based biosensors that function through various analytical methods including fluorescence, chemiluminescence, electrochemical and colorimetric in recent five years. The review may do some help to the researchers who are interested in 2D TMONs based biosensors.