TiC MXene-based nanozyme as coreaction accelerator for enhancing electrochemiluminescence of glucose biosensing.

Delamination of the exfoliated multilayer MXenes with electro-catalysts, not only leads to increasing surface area for high electrochemiluminescent (ECL) signal tracer loading but also provides highly sensitive achievements in a coreaction accelerator manner. To this end, herein, we used bromophenol blue (BPB)-delaminated multilayer TiC MXene as both a coreaction accelerator to promote the electrochemiluminescent (ECL) reaction rate of luminol (LUM) and the co-reactant HO and a substrate for retaining high loading of glucose oxidase (GOx)-conjugated polyethylene imine (PEI) along with luminophore species into more open structure of TiC MXene for sensitive detection of glucose. In the presence of glucose, in situ generating HO product through a GOx-catalyzed process could produce abundant OH radicals via the peroxidase-like activity of the BPB@TiC in the LUM ECL reaction. Moreover, decreasing the distance between the high-content LUM into the BPB@TiC and the generated OH, minimizes the decomposition of highly active OH, providing a superb ECL signal. Last, the proximity of incorporated GOx into the delaminated TiC MXene near the electrode allows efficient electron transfer between the electrode and enzyme. The integration of such amplifying effects endowed high sensitivity and excellent selectivity for glucose with a low limit of detection of 0.02 μM in the wide range of 0.01 μM-40,000 μM, enabling the feasibility of the glucose analysis in human serum samples. Overall, the enhanced ECL based on the BPB@TiC opens a new horizon to develop highly sensitive MXene-based ECL toward the field of biosensors.