Sensitive colorimetric detection of miRNA-155 via G-quadruplex DNAzyme decorated spherical nucleic acid Academic Article uri icon

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abstract

  • Rapid and sensitive detection of biomarkers enables monitoring patients' health status and can enhance the early diagnosis of deadly diseases. In this work, we have developed a new colorimetric platform based on spherical nucleic acid (SNA) and G-quadruplex DNAzymes for the identification of specific miRNAs. The simple hybridization between the target miRNA and two capture probes (capture probe 1 located at AuNP surface and free capture probe 2) is the working principle of this biosensor. The hybridization and duplex formation among probes and miRNAs led to a significant decrease in the intensity of color change. A linear relationship between the decrease of colorimetric signal and the amount of target molecules was witnessed from 1 to 100 nM for miRNA-155. Using this method, we were able to detect concentrations of miRNA-155 as low as 0.7 nM. Furthermore, the proposed sensing platform can be utilized profitably to detect miRNA-155 in real human serum samples. We further investigated the applicability of the proposed method in a microfluidic system which displayed promising results. In this project, A G-quadruplex based SNAzyme was constructed to provide a fast and simple colorimetric method for miRNA detection. The SNAzyme actually employed as both target recognition element and catalytic nano labels for colorimetric detection.

publication date

  • September 2022