Synthesis Of Selenol And PH Fluorescent Probes For Applications In The Detection Of Livestock Products

Fluorescent probes are one of the most functional tools in the fields of cell biology,developmental biology and medicine.Fluorescent probes are non-invasive,high inherent sensitivity,considerable detection selectivity,easy to operate,low cost,fast response,high time resolution and appropriate beneficial features for easy signal detection,so they are important tools in chemical and biochemical research.In recent years,the detection of residues in food,harmful substances,important ingredients in some functional products,and food freshness has attracted more and more attention.Selenols has an impact on the health of livestock and meat quality.The p H value is a very important indicator of meat quality,and the freshness of meat can be judged by the change of p H.Most of the fluorescent probes that have been reported for the specific detection of selenols and p H are used for in vivo experiments in cell models or animal models,and few fluorescent probes are used for rapid detection in food samples.This article contains the following three studies:1.Thiol-labeled fluorescent probe for labeling and distinguishing thioredoxin reductase.In this work,we designed and synthesized the fluorescent probe Nap-I for labeling biological thiols.By shielding the interference of thiols at low p H,we selectively label proteins containing selenol.The detection limit of probe Nap-I for bovine serum albumin in SDS-PAGE is 37.5 n M.Based on the probe Nap-I,the serum albumin content of Tan sheep is 38.82 g/L,and the hemoglobin content is 24.1 g/L.At the same time,we used the probe Nap-I to distinguish thioredoxin reductase from rat liver,and found that at p H=7.4,the activity of thioredoxin reductase 2 in mitochondria was significantly higher than thioredoxin reductase 1 in cytoplasm.At the same time,we also used Nap-I to label the thioredoxin reductase in the Tan sheep’s liver and longissimus dorsi muscle.2.Selenol-specific fluorescent probes for the detection of selenol in Tan sheep tissues and organs.In this work,an "off-on" type fluorescent probe Nap-DNB was designed and developed for the detection of biological selenol in vitro.In this experiment,a combination of a low p H detection environment and a more difficult reaction site was adopted to avoid the interference of a large number of biological thiols in biological samples.The probe Nap-DNB can completely respond to selenocysteine within 15 mins,with a detection limit of 7.2 n M.The probe Nap-DNB was successfully used for the detection of selenol in the serum,liver and longissimus dorsi of Tan sheep.Through comparison,it is found that the detection results of selenol using the fluorescent probe Nap-DNB are similar to the detection results of thioredoxin reductase and glutathione peroxidase by the commercial kit method.The detection results of the two methods have the result that the Se1.0 group is higher than the Se2.0 group.The fluorescent probe Nap-DNB can be used for the detection of selenol in selenium-enriched mutton samples.3.p H-responsive fluorescent probe for freshness evaluation of chicken breast.In this work,we designed and synthesized a fluorescent probe Nap-MOR sensitive to p H changes for p H measurement.The PET effect of 4-(2-aminoethyl)morpholine increases the fluorescence of naphthalimide as the p H value decreases.Based on the effective response of the probe Nap-MOR in weakly acidic and weakly alkaline environments,it can present a good linear relationship in the range of p H=4.5-8.By comparing the detection results of the fluorescent probe Nap-MOR and the p H meter,it is proved that the fluorescent probe Nap-MOR can evaluate the freshness of the chicken breast by measuring the p H of the chicken breast.In summary,three new fluorescent probe tools with excellent fluorescence performance have been constructed,which can be applied to the labeling of thiol-containing proteins and thioredoxin reductase,the rapid detection of selenols,and the evaluation of the freshness of chicken breast under different environmental and experimental conditions.It laid the foundation for the rapid detection of meat quality-related indicators in the food industry.