Portal de Periódicos da CAPES

Versatile Electrochemiluminescence and Photoelectrochemical Detection of Glutathione Using Mn 2+ Substitute Target by DNA-Walker-Induced Allosteric Switch and Signal Amplification

2019; American Chemical Society; Volume: 91; Issue: 21 Linguagem: Inglês

10.1021/acs.analchem.9b03990

1520-6882

Junjun Ge, Yu Zhao, Xiaoshan Gao, Hongkun Li, Guifen Jie,

Biosensors and Analytical Detection

Glutathione (GSH) serves vital functions in biological systems and associates with various human diseases. In this work, a versatile electrochemiluminence (ECL) and a photoelectrochemical (PEC) "signal on" biosensing platform were developed for a sensitive assay of GSH by a Mn2+-powered DNAzyme amplification strategy combined with DNA-walker-triggered allosteric conversion. First, MnO2 nanosheets were reduced to Mn2+ by GSH; then, Mn2+ as a substitute target triggered DNAzyme-assisted cleavage-cycling amplification to generate numerous DNA output (s3). Meanwhile, the DNA molecular machine was introduced to bridge signal probes for versatile biosensing, which included hairpin DNA as a track and an arm as a walker. The presence of DNA output (s3) activated the swing arm to hybridize with hairpin DNA and then cut it by Nt.BbvCI, which initiated autonomous walking of the arm for forming a large number of streptavidin (SA) aptamers. Thus, a large number of CdS:Mn-SA tags as versatile signal probes was linked to the electrode by specific SA-aptamer binding, generating highly enhanced ECL and PEC signals for sensitive detection of the target. The present biosensing system take advantage of metal ion-based DNAzyme amplification, a DNA walker machine, multi-signals of QDs, and specificity of aptamers, which can provide a universal and efficient biosensing method for detecting various targets. The designed strategy demonstrated good performance for a GSH assay in human serum samples, showing more promising applications than other reported methods.