A New Method for the Label-Free Detection of Vascular Endothelial Growth Factor Based on DNAzymes

The possibility of performing reliable cancer diagnosis even before any symptoms of disease appears is crucial for increasing therapeutic treatment success and patient survival rates. Herein, an ultrasensitive colorimetric sandwich sensor for vascular endothelial growth factor (VEGF) detection is introduced. The peroxidase-like DNAzyme catalyzes the oxidation of 2,2′-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid, which generates a blue–green colorimetric signal. This method can detect VEGF at a concentration as low as 10 nM. This strategy will be a promising tool for bioanalytical and clinical applications.