Indirect Detection of Chromium using Monoliths and Sol-gels

Abstract

The use of sol-gels as a chemical sensing matrix is attractive due to many of the unique physical and chemical properties they exhibit. In the current work, pyridine functionalized sol-gels were studied for their potential application in spectroelectrochemical sensing. Bulk sol-gel monoliths of varying formulations were tested to determine the optimal concentration of charge selective pyridine functional groups within the ion selective sensing sol-gel matrix. Process variables were investigated in order to produce uniform monoliths and material performance was tested by fluorescence spectroscopy. Once optimal formulations are determined, tests will be conducted on thin film electrodes which provide three modes of selectivity by means of chemically selective sol-gel films, electrochemical activity, and/or optical properties of the fluorescent redox probe, Ru(bpy)₃² for the indirect simultaneous optical and electrochemical detection of Cr⁶⁺.