Ag-MXene as peroxidase-mimicking nanozyme for enhanced bacteriocide and cholesterol sensing

•The prepared Ag-MXene artificial nanozyme showed high peroxidase-like activity.•The nanocomposite could enhance the antibacterial activity, and effectively disrupt the bacterial biofilm formation as well.•The peroxidase-like activity of Ag-MXene was coupled with cholesterol oxidase to realize the cholesterol detection.•The total cholesterol content in human serum samples have been successfully determined with satisfactory accuracy.