G-Quadruplex-Based DNAzyme as a Sensing Platform for Ultrasensitive Colorimetric Adenosine Deaminase Detection

Abstract

Adenosine deaminase plays a crucial role in the development and maintenance of the normal immune system. Although the determination of adenosine deaminase in serum may serve as a noninvasive diagnostic tool in evaluation of the active phase of systemic lupus erythematosus and the severity of this disease, detection of this analyte in a biologically complex mixture remains a major challenge. In this report, a colorimetric biosensor is reported for the determination of adenosine deaminase activity. The sensor employed DNAzyme as the signal transformation element which does not have a complicated label process. The proposed method was simple, rapid, and economical, allowing monitoring of adenosine deaminase to levels less than 0.1 U L⁻¹. The simplicity of this device suggests it may be a candidate for the rapid screening of proteins in human serum and have wide applications in the field of clinical diagnosis.

Keywords:

• Adenosine deaminase
• Clinical diagnosis
• DNAzyme
• Enzyme assays
• Hemin

Acknowledgments

The authors are very grateful to the Natural Science Foundation of Jiangsu Province (BK2011168, BK2012105) and the Economic and Social Development Foundation of Wuxi (CSZ01010).