Optical Absorption and Fluorescence of NADH Encapsulated Sol-Gel Silicate Gels

Abstract

Reduced nicotinamide adenine dinucleotide (NADH) was encapsulated in transparent porous sol-gel silicate gels using by different organoalkoxysilane precursors. Characteristic optical absorption and fluorescence of NADH in the gels were examined with depending on NADH concentration and compared. Optical absorption in the aminopropyltrimethoxysilane (APTMS) gel is highest and remains constant during aging the gel. Thus, it is found that NADH in the APTMS gel is most stable and activated. On the other hand, methyltriethoxysilane (MTES) gel presents the lowest optical absorption diminishing with aging the gel. Measurement increase of fluorescence with raising the NADH concentration is observed except for the APTMS gel due to its solubility in the buffer during fluorescence measurement.