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A Universal Paper-Based Electrochemical Sensor for Zero-Background Assay of Diverse Biomarkers

Liu, Xiaojuan, Li, Xiuyuan, Gao, Xin, Ge, Lei, Sun, Xinzhi, Li, Feng
ACS applied materials & interfaces 2019 v.11 no.17 pp. 15381-15388
DNA, alkaline phosphatase, antigens, biomarkers, blood serum, electrochemistry, electrodes, microRNA, oligonucleotides, paper, point-of-care systems, polymerization, sensors (equipment)
This paper describes a universal paper-based electrochemical sensing platform that uses a paper modified with signal molecule-labeled DNA and a screen-printed electrode along with target recognition solutions to achieve the detection of multiple types of biomarkers. These assays rely on the target-induced synthesis of Mg²⁺-dependent DNAzyme for catalyzing the cleavage of substrate DNA from paper, which have been demonstrated by using microRNA recognition probe for miR-21, a phosphorylated hairpin probe for alkaline phosphatase, and a DNA aptamer for carcinoembryonic antigen assays, respectively. Taking advantages of the high specific target-triggered polymerization/nicking and DNAzyme-catalyzed signal amplification, the present assays enable highly sensitive and selective detection of these targets with zero-background. These assays can also be applied to detect target in spiked serum samples, demonstrating the potential for point-of-care detection of clinical samples.