Aptamer-based flares hybridized with single-stranded DNA-conjugated MoS2 nanosheets for ratiometric fluorescence sensing and imaging of potassium ions and adenosine triphosphate in human fluids and living cells

•Conjugation of MoS2 nanosheets with flares via a one-step process.•ssDNA-SH-modified MoS2 nanosheets were hybridized with FAM and TAMRA labeled flares.•G4- and Apt-MoS2 nanosheets can be applied as a nanoprobe for imaging real samples.•High analyte concentrations are required to detach flares from the MoS2 nanosheets.•MoS2 nanosheets as a nanocarrier for DNA-based flares.