A triethoxysilyl-functionalized cyclometallated platinum(II) complex Pt(MeOPhC boolean AND N boolean AND N)X (where MeOPhCN boolean AND N=C-anion of 3-phenyl-5-p-methoxylphenyl-2,2'-bipyridine and X=NH2(CH2)(3)Si(OCH2CH3)(3)) was homogeneously incorporated into sol-gel glass by cocondensation with Si(OCH2CH3)(4). The resultant luminescence shows a rapid and sensitive response to oxygen gas : 58% luminescence is quenched in ca. 10 s when switching from dinitrogen to dioxygen.