TY - JOUR A1 - Ida, Jeunice A1 - Chan, Soo Khim A1 - Glökler, Jörn A1 - Lim, Yee Ying A1 - Choong, Yee Siew A1 - Lim, Theam Soon T1 - G-Quadruplexes as An Alternative Recognition Element in Disease-Related Target Sensing JF - Molecules N2 - 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. KW - G-quadruplex KW - DNAzyme KW - colorimetric KW - fluorescence KW - luminescence KW - diagnostics Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-11438 SN - 1420-3049 VL - 24 IS - 6 ER - TY - JOUR A1 - Kagel, Heike A1 - Bier, Frank Fabian A1 - Frohme, Marcus A1 - Glökler, Jörn T1 - A Novel Optical Method To Reversibly Control Enzymatic Activity Based On Photoacids JF - Scientific Reports N2 - Most biochemical reactions depend on the pH value of the aqueous environment and some are strongly favoured to occur in an acidic environment. A non-invasive control of pH to tightly regulate such reactions with defined start and end points is a highly desirable feature in certain applications, but has proven difficult to achieve so far. We report a novel optical approach to reversibly control a typical biochemical reaction by changing the pH and using acid phosphatase as a model enzyme. The reversible photoacid G-acid functions as a proton donor, changing the pH rapidly and reversibly by using high power UV LEDs as an illumination source in our experimental setup. The reaction can be tightly controlled by simply switching the light on and off and should be applicable to a wide range of other enzymatic reactions, thus enabling miniaturization and parallelization through non-invasive optical means. Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-12685 SN - 2045-2322 VL - 9 ER - TY - JOUR A1 - Kagel, Heike A1 - Jacobs, Hannes A1 - Bier, Frank Fabian A1 - Glökler, Jörn A1 - Frohme, Marcus T1 - A Novel Microtiter Plate Format High Power Open Source LED Array JF - Photonics N2 - Many photochemical or photobiological applications require the use of high power ultraviolet light sources, such as high-pressure mercury arc lamps. In addition, many photo-induced chemical, biochemical and biological applications require either a combinatorial setting or a parallel assay of multiple samples under the same environmental conditions to ensure reproducibility. To achieve this, alternative, controllable light sources, such as ultraviolet light emitting diodes (UV LEDs) with high power and spatial control are required. Preferably, LEDs are arranged in a suitable standardized 96-well microtiter plate format. We designed such an array and established the methods required for heat management and enabling stable, controllable illumination over time. KW - optics KW - photonics KW - light KW - LED array KW - High-power LED KW - 365 nm KW - microtiter plate Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-11307 SN - 2304-6732 VL - 6 IS - 1 ER - TY - JOUR A1 - Kagel, Heike A1 - Frohme, Marcus A1 - Glökler, Jörn T1 - Photoacids in biochemical applications JF - Journal of Cellular Biotechnology N2 - BACKGROUND: After excitation with light photoacids can change the pH in a solution by release of a proton. They have been used mostly for excited state proton transfer studies. In this review the general functionality and mechanisms and the subdivision of photoacids is explained. STATE OF THE ART: Different uses of photoacids are described, covering a wide range of various biochemical topics, focusing on biochemical applications. Examples for the introduced subdivisions are covered. CONCLUSIONS AND OUTLOOK: The areas in which photoacids can be employed are diverse. Photoacids have a promising future in biotechnology and biochemistry and should be considered for upcoming applications, especially in non-invasive control of biochemical reactions. Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-16123 SN - 2352-3697 VL - 4 IS - 1-2 SP - 23 EP - 30 PB - IOS Press ER -