Sol-gel based matrix

A sol-gel matrix comprising:

• a first polymer component prepared from polymerization of a first alkoxysilane of the general formula R1—Si(OR2)3 and an additional alkoxysilane of the formula R5—Si(OR2)3,
• a second sol-gel component comprising a Lewis acid and a second polymer component prepared from Lewis acid catalyzed polymerization of a second alkoxysilane of the general formula
• wherein
• R1 is selected from the group consisting of a straight and branched C1-C6 alkyl, a C2-C6 alkenyl, a C3-C6 cycloalkyl, a C1-C6 aminoalkyl, a C1-C6 hydroxyalkyl, a C1-C6 cyanoalkyl, a phenyl, and a group of the formula —Y—(X—Y)nH, with Y being independently selected from the group consisting of straight and branched C1-C6 alkylene, X being a hetero atom or group selected from the group consisting of O, S, and NH, and n being an integer of 1-5, or R1 represents a C1-C6 alkyl substituted with a group Z, with Z being independently selected form the group consisting of hydrogen, cyano, halogen, hydroxy, nitro, amide C1-C24-alkyl, C1-C24-haloalkyl, C2-C24-alkenyl, C2-C24-alkynyl, aryl, C1-C24-alkoxy, C1-C24-alkylsulfonyl, amino, aminocarbonyl, aminothiocarbonyl, aminocarbonylamino, aminothiocarbonylamino, aminocarbonyloxy, aminosulfonyl, aminosulfonyloxy, aminosulfonylamino, amidino, carboxyl, carboxyl ester comprising a C1-C6 alkyl alcohol moiety, (carboxyl ester)amino comprising a C1-C6 alkyl alcohol moiety, (carboxyl ester)oxy comprising a C1-C6 alkyl alcohol moiety, sulfonyl, sulfonyloxy, thiol, thiocarbonyl, C1-C24-alkylthio, 5 or 6 membered heteroaryl, and a C3-C7 cycloalkyl;
• R2 independently represents a straight or branched C1-C6 alkyl;
• R3 represents a linker selected from a group of the formula —R4—(X—R4)0-12—, wherein R4 is independently selected from straight or branched C2-C6 alkylene, C2-C24-haloalkylene, and X is a hetero atom or group selected from the group consisting of 0, S and NH;
• and
• R5 represents a group of the general formula
• —R3—NH—C(═O)—X—R3-Q
• wherein R3 and X are as defined above and independently selected, and Q represents an indicator and/or a reference dye derived from triangulenium compounds, acridinium compounds, ruthenium doped sol-gel particles, ruthenium-based compounds with α-diimine ligands, porphorin with Pt or Pd as the central metal atom, Ru(bpy)2(dpp)Cl2, Ru(bpy)3Cl2 a lanthanide containing complex, or polymeric metal containing structure.