Advances in the Use of Sol-Gel-Derived Microarrays as an Assay and Detection Platform

Abstract

The use of sol-gel immobilization in the fabrication of microarrays is a relatively new approach that has shown potential to become a leading methodology in this field. However, there are a limited number of assay systems that have been reported using this method. Furthermore, methods to produce high-density sol-gel-derived microarrays have not been reported. Herein, two novel assays utilizing sol-gel-derived microarrays are presented. In the first case, the solid phase of sol-gel-derived microarrays was employed as a detection platform for monitoring the activity of glycogen synthase kinase 3-β (GSK3β) in solution using a phosphospecific stain. Using this assay format, the ability to detect hyperphosphorylated product over the pre-phosphorylated substrate was demonstrated and a z' value of 0.49 was obtained, indicating amenability to small molecule screening. Secondly, a fluorogenic assay for acetylcholinesterase (AChE) was development that is compatibility with sol-gel derived microarrays and standard imaging instrumentation. A thiol-reactive fluorogenic dye, typically used for detection of thiolated oligonucleotides, was successfully used to monitor AChE activity both in solution and in silica. Further, a functional sol-gel-derived AChE microarray was fabricated and activity on array was detected. We have also reported on the optimization of materials for the fabrication of high-density kinase microarrays using sol-gel immobilization. By employing a directed criteria-based screen, optimal materials were quickly and efficiently identified. Two materials, 1.5SS/1PV A/Glycerol and 0.25DGS, were identified as the optimal materials for fabrication of sol-gel-derived functional microarrays.