thrombin-aptamer and 2-2--azino-di-(3-ethylbenzothiazoline)-6-sulfonic-acid

In this work, a convenient and high-throughput colorimetric assay was developed on an aptamer-modified microchip for ultrasensitive detection of thrombin using rolling circle amplification and G-quadruplex DNAzyme. This system consisted of an aptamer-modified microchip and a secondary aptamer. The secondary aptamer contained a thrombin aptamer and a primer with a G-quadruplex circular template. RCA technology was used to improve the sensitivity by producing the multiple G-quadruplex units. To generate colorimetric signal, G-quadruplex DNAzyme was used to catalyze the H2O2-mediated oxidation of 2,2'-azinobis (3-ethylbenzothiozoline)-6-sulfonic acid. At the optimal conditions, the linear range for thrombin was 0.100-50.000 pg/mL, and the limit of detection was down to 0.083 pg/mL. Moreover, the developed method was successfully applied to detect thrombin from human plasma and serum, indicating that this approach has great potential in clinical diagnosis and medical investigation.

Topics: Aptamers, Nucleotide; Base Sequence; Benzothiazoles; Biosensing Techniques; Colorimetry; DNA, Catalytic; Equipment Design; G-Quadruplexes; Hemin; High-Throughput Screening Assays; Humans; Hydrogen Peroxide; Microfluidic Analytical Techniques; Molecular Sequence Data; Nucleic Acid Amplification Techniques; Oxidation-Reduction; Sulfonic Acids; Thrombin