Improving the synthesis of a serine molecularly imprinted sol-gel using a Plackett–Burman design.

Alfonso Fernández-González, Rosana Badía-Laíño, Marta Elena Díaz-García Departament of Physical and Analytical Chemistry Faculty of Chemistry. University of Oviedo. Av. Julián Clavería, 8 ES-33006-Oviedo. Spain [email protected] Design of Placket-Burmann experiment. A, presence of 3-APTEOS; M, presence of MTMOS; F, presence of FTBA; R, ratio ethanol/water; B basic catalysis. Li latent factor.

A M L1 F L2 R L3 L4 L5 B L6 Sol-Gel + + - + + + - - - + - 1SG - + + - + + + - - - + 2SG + - + + - + + + - - - 3SG - + - + + - + + + - - 4SG - - + - + + - + + + - 5SG - - - + - + + - + + + 6SG + - - - + - + + - + + 7SG + + - - - + - + + - + 8SG + + + - - - + - + + - 9SG - + + + - - - + - + + 10SG + - + + + - - - + - + 11SG ------12SG Composition of sol-gels. Serine solution was 10-2 M; FTBA solution was 0.025 M; HCl and NaOH were 0.1 M, added in a 50 L aliquot. Notation: N: non-imprinted material, I: imprinted sol-gel

Name Ethanol Water Serine FTBA TEOS MTMOS 3APTEOS Catalyst 1SGN 2333 367 0 750 500 500 500 NaOH 1SGI 2333 250 117 750 500 500 500 NaOH 2SGN 2333 1117 0 0 750 750 0 HCl 2SGI 2333 1000 117 0 750 750 0 HCl 3SGN 2333 367 0 750 750 0 750 HCl 3SGI 2333 250 117 750 750 0 750 HCl 4SGN 1167 1533 0 750 750 750 0 HCl 4SGI 1167 1416 117 750 750 750 0 HCl 5SGN 2333 1117 0 0 1500 0 0 NaOH 5SGI 2333 1000 117 0 1500 0 0 NaOH 6SGN 2333 367 0 750 1500 0 0 NaOH 6SGI 2333 250 117 750 1500 0 0 NaOH 7SGN 1167 2283 0 0 750 0 750 NaOH 7SGI 1167 2166 117 0 750 0 750 NaOH 8SGN 2333 1117 0 0 500 500 500 HCl 8SGI 2333 1000 117 0 500 500 500 HCl 9SGN 1167 2283 0 0 500 500 500 NaOH 9SGI 1167 2166 117 0 500 500 500 NaOH 10SGN 1167 1533 0 750 750 750 0 NaOH 10SGI 1167 1416 117 750 750 750 0 NaOH 11SGN 1167 1533 0 750 750 0 750 HCl 11SGI 1167 1416 117 750 750 0 750 HCl 12SGN 1167 2283 0 0 1500 0 0 HCl 12SGI 1167 2166 117 0 1500 0 0 HCl OEt CH3

EtO Si OEt CH3O Si OCH3 O OEt OCH H2N C 3 CH OH

Tetraethoxysilane Methyltrimethoxysilane CH2 OEt OH Si OEt Serine H2N CH2 CH2 CH2

OEt 3-aminopropyltriethoxysilane

Chemical structures of serine, tetraethoxysilane, methyltrimethoxysilane and 3- aminopropyltriethoxysilane.