A Turn-Off Fluorescent Strategy for Calprotectin Detection Based on the Inhibitory Effect of Calprotectin upon the Activity of Zn(II)-Dependent DNAzyme

Calprotectin (CP) is an established biomarker that allows the noninvasive evaluation of inflammation levels in the gastrointestinal tract of patients with inflammatory bowel disease and is helpful for the diagnosis and management of the disease. Herein, we demonstrate that CP can effectively suppress the activity of 17E DNAzyme (17E) by chelating Zn(II), which is the cofactor of 17E. As the inhibition efficiency of CP on the DNAzyme is proportional to the concentration of CP, the detection of CP can be readily achieved by assessing the activity of 17E.