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Mesoporous aluminas(MAs)with high thermal stability and tunable pore sizes were synthesized.The general synthesis strategy was based on a sol-gel process associated with Pluronic P123 as templates in ethanol solvent.These mesoporous aluminas have large surface areas,pore volumes and narrow pore-size distributions,which is an excellent advantage in oxygen sensing[1,2].The water-soluble carbon dots(CDs)were prepared by one-pot hydrothermal treatment of poly(vinyl alcohol)(PVA)and ethylenediamine(EDA),and a stable yellow powder was obtained via freeze-drying.CDs exhibit strong yellow-green solid-state fluorescence(SSF)in the aggregation state as well as blue fluorescence in water or solid matrices,and first realized a tunable SSF by surface modification or interparticle spacing control[3].Luminescent carbon dots(CDs)were assembled into MAs with different CDs/MAs molar ratios of 2.5％,5.0％,10％,15％,20％,and 25％.The assembled CDs/MAs were characterized by nitrogen absorption analysis,small-angle X-ray diffraction,transmission electron microscopy and so on.Various characterization results showed that MAs possessed relatively high surface area(409 m2/g)with narrow pore sizes(3-10 nm)distribution after calcination at 800℃,fluorescent CDs can be finely assembled into the channels of MAs.CDs/MAs had extremely high sensitivity and selectivity to oxygen.CDs/MAs(20％)had strongest luminescent intensity,best oxygen sensing properties and high sensitivity(I0/I100)up to 4.79.The response time was about 4-8 s.As-prepared CDs/MAs samples had reversible oxygen sensing signal and good photochemical stability.So the system can be used for oxygen detection in wide concentration range and was especially accurate for very low oxygen concentrations.