A universal amplified strategy for aptasensors: Enhancing sensitivity through allostery-triggered enzymatic recycling amplification

作者：Feng, Kejun; Kong, Rongmei; Wang, Hua; Zhang, Shufang; Qu, Fengli^*

来源：Biosensors and Bioelectronics, 2012, 38(1): 121-125.

DOI：10.1016/j.bios.2012.05.008

• Aptasensors
• Fluorescence
• IgE
• Enzymatic recycling amplification
• Biological samples

A universal amplified sensing strategy based on endonuclease was developed for designing fluorescence aptasensors. By employing hairpin-structured design for both recognition and reporter probes to decrease background signal, and a nicking endonuclease to perform target-triggered enzymatic recycling amplification, the proposed biosensor showed high sensitivity to target protein. To demonstrate the feasibility of the design, immunoglobulin E (IgE) was studied as a model target. Upon the addition of target protein, the specific formation of IgE/aptamer complex induced the releasing of the 37-mer fragment which partially hybridized with the molecular beacon (MB) probe. In the presence of endonuclease Nt.BbvCI, the MB was cleaved into two parts. Then, the released 37-mer fragment hybridized with another MB, and triggered the second cycle of cleavage, leading to an accumulation of fluorescence signals. Under the optimal conditions, a detection limit of 5 pM was obtained. The proposed sensing system was used for detection of IgE in complex biological samples with satisfactory results.

• 出版日期2012-12
• 单位惠州学院; 曲阜师范大学