A shining proposal for the detection of dissolved O2 in aqueous medium: Self-calibrated optical sensing via a covalent hybrid structure of carbon-dots&Ru

•An optical oxygen sensing platform for the detection of dissolved O2 in aqueous medium was reported.•We tried the combination of Ru(II)-bpy complex and carbon dots (CDs) via covalent bonds.•Self-calibrated sensing signal for dissolved oxygen was observed.•A good linearity of 99.1% and a high sensitivity (2.18) were reported, along with good selectivity and signal stability.