Cleaved DNAzyme substrate induced enzymatic cascade for the exponential amplified analysis of l-histidine

• Published in: Talanta (Oxford) 2015-01, Vol.132, p.809-813
• Main Authors: He, Jing-Lin, Wu, Ping, Zhu, Shuang-Li, Li, Ting, Li, Pan-Pan, Xiang, Jian-Nan, Cao, Zhong
• Format: Article
• Language: English
• Subjects: Biocatalysis; Biosensing Techniques; DNA Polymerase I - chemistry; DNA, Catalytic - chemistry; Electrophoresis, Agar Gel; Endonucleases - chemistry; Enzymatic cascade; Exponential amplified analysis; Fluorescence; Histidine - analysis; Hydrolysis; l-Histidine; Limit of Detection; Oligonucleotides - chemistry; Self-cleaved DNAzyme; Solutions
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2014.10.037

A novel strategy of cleaved DNAzyme substrate induced enzymatic cascade has been devised for the exponential amplified detection of l-histidine. The enzyme strand carries out hydrolytic cleavage of the substrate strand in the presence of l-histidine. The cleaved DNAzyme substrates introduce the polymerase/endonuclease reaction cycles as primers. The l-histidine acts as the activator for enzymatic cascade amplification generating a distinguishable fluorescence enhancement. A good nonlinear correlation (R=0.9994) between fluorescence intensity and the logarithm of the l-histidine concentration is obtained over the range from 50nM to 1.0mM. The detection limit was estimated as 30nM. This efficient amplification of the fluorescence signal is attributed to the l-histidine induced cooperation of Klenow Fragment polymerase (exo−) and Nb.BbvCI endonuclease reaction. The activation of such enzymatic cascades through analyte-DNAzyme interactions has a substantial impact on the development of exponential amplified DNAzyme sensors. Schematic representation of the DNAzyme based enzymatic cascade strategy for the amplified detection of l-histidine. [Display omitted] •A DNAzyme based enzymatic cascade strategy was developed for the exponential amplified of l-histidine.•l-Histidine could catalyze the hydrolytic cleavage of DNAzyme.•The cooperation of KF polymerase and Nb.BbvCI endonuclease reaction results in an efficient increase of the fluorescence signal.