Organically and bio-organically doped sol−gel materials have attracted much attention due to their ability to reproduce solution molecular activities within the ceramic environment. We take now this methodology one step forward and explore conditions under which the dopant properties can be modified by the matrix. Specifically we report that the co-entrapment of the surfactant cetyltrimethylammonium bromide (CTAB, the modifier) at low concentrations, with an extensive series of pH indicators representing several key molecular families (the primary dopant) within tetramethoxysilane (TMOS)-derived silica sol−gel matrixes, greatly modifies the indicating performance of the primary dopant.
In addition to a pH indicator, cresol red can also be used as a molecular weight marker in the agarose gel electrophoresis and polyacrylamide gel electrophoresis to track the progress, so your DNA, RNA, or protein will not run off the gels.
Warm 0.1 g of cresol red in a mixture of 2.65 ml of 0.1 M sodium hydroxide and 20 ml of ethanol .