An efficient fluorescent sensing platform for biomolecules based on fenton reaction triggered molecular beacon cleavage strategy

A universal sensing platform for fluorescence turn-on detection of biomolecules is developed based on Fenton reaction triggered molecular beacon cleavage. Due to its high quenching efficiency, molecular beacons (MBs)-based sensing systems usually show low background fluorescence and large signal-to-background ratio. Glucose is chosen as a model biomolecule for constructing an MB-based fluorescence sensing system. In the presence of glucose, the glucose oxidase will bind with it and catalyze the oxidation to generate H2O2, which is further decomposed to produce center dot OH through the Fe2+-catalyzed Fenton reaction. Then, in-situ-generated OH can trigger the cleavage of the MB, and its fluorescence intensity will be dramatically increased because of the complete separation of the fluorophore from the quencher. By employing molecular beacon as both recognition and reporter probes to low background signal, the proposed biosensors showed high sensitivity to targets. It also exhibited high selectivity owing to the high specificity of the enzymatic oxidation, which make it valuable for the detection of target biomolecule in complex biological samples. (C) 2012 Elsevier B.V. All rights reserved.