Chem. Commun.: a new type of bioanalytical test object using touch instead of vision

Among all kinds of analytical methods, those that can display the detection results by directly outputting visual signals are particularly attractive because they do not need to use instruments and complex analytical processes At present, pH test, home pregnancy test, enzyme-linked immunosorbent assay (ELISA), gold nanoparticle based DNA analysis are very good in the readability of the output signal However, this detection method also has limitations For the blind or color blind, or under the condition of invisibility, these detection methods will have no use Therefore, researchers consider challenging this situation and hope to change this single non instrument detection method by using a new touchable detection method, so as to facilitate the use of blind people and color blind people, or allow to provide detection means for analysts under the conditions of no visualization such as darkness Tatiana fedotova and Dmitry kolpashchikov from the University of Central Florida in the United States have designed a new method, which can be used for the detection of biological analytes, and the expression of detection results can be achieved by tactile means The method is based on the free radical polymerization of acrylamide and polyacrylamide in horseradish peroxidase (HRP) / acylacetone / H 2O 2 ternary system In this system, acetylacetone is oxidized to acetylacetone radical by HRP, then free radical initiating acrylamide polymerization, and macroscopic performance of gel liquid transition However, HRP itself is not easily transformed into a sensor capable of detecting biological analytes On the other hand, many DNA and RNA sequences have been reported to have HRP like activity in the presence of hemin Peroxidase like DNAzymes (PXD) contains guanine rich DNA sequence, which can be folded into a stable G-quadruplex structure It can combine with hemin and catalyze colorless substance to transform it into colored product So far, a variety of colorimetric biosensors have been developed based on PXD Based on the polymerization reaction to detect amel? X (source: chem Commun.), therefore, the research goal of the researchers is to activate the analysis response of PXD, and then trigger the polymerization of acrylamide solution instead of color change If the polymerization is successful, the gel fragments can be observed by inverted centrifuge tube or the gel fragments can be observed through touch on the filter paper In the proof of concept study, they reported the detection of biological important analytes: ATP and two DNA sequences (AMEL_X and AMEL_Y) were expressed by liquid gel transition Importantly, PXD based sensors can be used to detect various analytes, including metal ions, small molecules and proteins Therefore, this method is widely used in biological analysis However, it is sensitive to oxygen in the atmosphere Oxygen inhibits polymerization and complicates quantitative analysis The solution may only be to isolate the detection space of oxygen, or to improve free radicals and polymers, which can not be affected by oxygen The non polymerized acrylamide is toxic, but can be solved by gloves or film covering Detection of amel_y (source: chem Commun.) in non logic mode, this new signal output mode may have great potential to surpass the tactile platform, such as adjusting the flow state of the fluid in the pipeline through the response object, and making it solid where necessary At the same time, researchers also need this method to provide a convenient home test system for blind and color blind people, and stimulate the future development of chemical products for people with physical disorders Paper link: http://pubs.rsc.org/en/content/articlelanding/2017/cc/c7cc07035g ×! Divabstract