@article{IdaChanGloekleretal.2019, author = {Ida, Jeunice and Chan, Soo Khim and Gl{\"o}kler, J{\"o}rn and Lim, Yee Ying and Choong, Yee Siew and Lim, Theam Soon}, title = {G-Quadruplexes as An Alternative Recognition Element in Disease-Related Target Sensing}, series = {Molecules}, volume = {24}, journal = {Molecules}, number = {6}, issn = {1420-3049}, doi = {10.3390/molecules24061079}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-11438}, year = {2019}, abstract = {G-quadruplexes are made up of guanine-rich RNA and DNA sequences capable of forming noncanonical nucleic acid secondary structures. The base-specific sterical configuration of G-quadruplexes allows the stacked G-tetrads to bind certain planar molecules like hemin (iron (III)-protoporphyrin IX) to regulate enzymatic-like functions such as peroxidase-mimicking activity, hence the use of the term DNAzyme/RNAzyme. This ability has been widely touted as a suitable substitute to conventional enzymatic reporter systems in diagnostics. This review will provide a brief overview of the G-quadruplex architecture as well as the many forms of reporter systems ranging from absorbance to luminescence readouts in various platforms. Furthermore, some challenges and improvements that have been introduced to improve the application of G-quadruplex in diagnostics will be highlighted. As the field of diagnostics has evolved to apply different detection systems, the need for alternative reporter systems such as G-quadruplexes is also paramount.}, language = {en} } @article{OmarLohTyeetal.2013, author = {Omar, Noorsharmimi and Loh, Qiuting and Tye, Gee Jun and Choong, Yee Siew and Noordin, Rahmah and Gl{\"o}kler, J{\"o}rn and Lim, Theam Soon}, title = {Development of an Antigen-DNAzyme Based Probe for a Direct Antibody-Antigen Assay Using the Intrinsic DNAzyme Activity of a Daunomycin Aptamer}, series = {Sensors}, volume = {14}, journal = {Sensors}, number = {1}, issn = {1424-8220}, doi = {10.3390/s140100346}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:526-opus4-6267}, pages = {346 -- 355}, year = {2013}, abstract = {G-Quadruplex (G-4) structures are formed when G-rich DNA sequences fold into intra- or intermolecular four-stranded structures in the presence of metal ions. G-4-hemin complexes are often effective peroxidase-mimicking DNAzymes that are applied in many detection systems. This work reports the application of a G-rich daunomycin-specific aptamer for the development of an antibody-antigen detection assay. We investigated the ability of the daunomycin aptamer to efficiently catalyze the hemin-dependent peroxidase activity independent of daunomycin. A reporter probe consisting of biotinylated antigen and daunomycin aptamer coupled to streptavidin gold nanoparticles was successfully used to generate a colorimetric readout. In conclusion, the daunomycin aptamer can function as a robust alternative DNAzyme for the development of colorimetric assays.}, language = {en} }