Detection Of MiRNAs And Gluconic Acid-regulated AuNPs Synthesis

MicroRNAs were first discovered in the research on C.elegans, and they are widely distributed among germs、fungus and various kinds of orgamisms. Generally speaking, microRNAs are21～23nucleotides endogenous short non-coding single-stranded RNAs. By binding to the3’ UTR、5’ UTR and ORF of target mRNAs, microRNAs regulate the translation of proteins from mRNA or degrade the mRNA itself, and play an important role in cell differentiation、proliferation、metabolism and apoptosis. There are more than500hundred miRNAs in human body, and they regulate the normal cell circle to keep healthy. So it is of great importance to build up some methods to detect the concentration of miRNAs in germs、fungus, as well as diseases, as they are playing a vital role to regulate normal life circle. And research on detection of different miRNAs play a special role on research on cancer process and prognosis. In my study, by combing RCA with NESA, we successfully have some miRNAs detected in total RNA which was extracted from cancer tissues and peri-cancer tissues of esophageal squamous cell carcinoma. The results have shown expression diversity of the same microRNA among different individuals and miRNAs expression is up-regulated in cancer tissues. This indicates that aberrant expression of these miRNAs have some relations to the process of esophageal squamous cell carcinoma.AuNPs is a kind of materials of many application, it has a good biocompatibility and can react with many biological macromolecules without change their properties. It is widely reported that AuNPs could be used as probes to detect RNA、DNA as well as germs. However, surfactants are applied in the synthesis of AuNPs, and do bad to the application of AuNPs in the study of germs or cell researches. A previous study has shown gluconic acid absorb on the particular crystal facet of AuNPs. Based on this fact, we use gluconic acid as capping agent and reductant, by controlling the concentration、temperature、pH and O2, in order to obtain AuNPs with a particular shape and further use them to detect miRNAs. However, by changing some parameters, we found that we could only get some triangular or hexagonal Au nanoplates with low quantity. This means gluconic acid indeed could absorb on a particular facet, however, these absorption ability is too low to block all the facet, leading to the birth of AuNPs with mixted shapes.