Construction Of Platinum-Based Nanomimetic Enzyme And Its Application In Food Detection

Point-of-care testing is a new type of method that immediately performs analysis at the sampling site,eliminating the need for complicated processing procedures during laboratory testing of samples,and quickly obtaining test results.Due to the rapidity and convenience of real-time detection,it is very suitable for food safety analysis and detection.With the rapid development of nanotechnology,biosensing technology based on nanomaterials has great potential in designing high-sensitivity and high-selectivity food safety detection strategies.Noble metal nanomaterials are widely used in constructing simple and fast real-time detection methods due to their high-efficiency catalytic activity,excellent stability and easy surface modification.Based on the unique chemical properties of the precious metal platinum nanomaterials,this paper constructs an instant detection method with simple operation,low cost,good portability and high sensitivity,and is applied to the field of food safety detection.1)Hypoxanthine(Hx)is the main catabolite of adenosine triphosphate(ATP)in the body when the quality of fish products changes.After the fish die,the ATP in the body is degraded to form hypoxanthine under the action of enzymes.Therefore,the accurate and rapid determination of Hx content in fish meat is helpful to evaluate the freshness of aquatic products,and has important guiding significance for ensuring the safety of aquatic products.In this article,a simple and fast colorimetric analysis method is developed for the detection of Hx.Hx can specifically recognize and inhibit the catalytic activity of the synthesized platinum cube(PVP-Pt NC)nanomaterials.Based on the color change of the catalytic chromogenic substrate before and after the inhibited reaction,the high Hx can be achieved by naked eye and UV-vis measurement.Sensitive detection.The method is simple in operation,low in cost,and the detection sensitivity can reach 0.96?M.In addition,through the addition of standard recovery experiments on actual samples,the recovery rate of addition is within an acceptable range,indicating that this method can be used for the visual detection of actual fish freshness samples in aquatic products.2)Silver is one of the most widely used heavy metals on the market.Due to its good photoelectric,catalytic,superconducting and sterilizing properties,silver is widely used.The mass production and wide application of silver increase the chance of its release to the environment,and at the same time increase its chance of contacting the human body.The free silver ion Ag(I)is currently recognized as one of the toxic metals.In this article,based on Ag(I)that can adjust the catalase activity of platinum nanoparticles(AA-Pt NPs),a miniature drainage device that uses weight changes as a signal to read is constructed,and a simple,fast,and highly sensitive Ag(I)Instant detection.The enzyme catalytic activity of AA-Pt NPs material is inhibited by Ag(I),which leads to a significant reduction in the amount of O₂produced by catalyzing H₂O₂.The micro drainage device we made can sensitively identify changes in air pressure,and output the results through drainage,and then pass the precision electronic balance reads the result of the mass weighing of the discharged water.Based on this,as the concentration of Ag(I)increases,the catalytic activity of the AA-Pt NPs material gradually weakens,resulting in a gradual decrease in the drainage volume of the micro-drainage device.Under the best experimental conditions,the detection limit of this method is 2 n M,and the detection range is 5-250 n M.In addition,H₂O₂was added during the experiment,and Ag NPs can be completely decomposed into Ag(I)after adding a very small amount of H₂O₂,so Ag NPs can also be detected.The detection limit for Ag NPs is 3.8 p M,and the detection range is 10-300 p M.Compared with the traditional detection method of silver-containing substances,this method is simple to operate,has high sensitivity,good selectivity,can detect Ag(I)and Ag NPs at the same time,and is suitable for on-site real-time detection of water environmental quality in remote or resource constrained areas.3)Hydrogen sulfide(H₂S)is recognized in recent years as the third endogenous gas signal molecule besides NO and CO.At the same time,H₂S is an important reason for the deterioration of wine quality.The H₂S in wine not only has a negative impact on the aroma of wine,but also faces food safety issues.In this article,after incubating the headspace of H₂S gas with platinum nanoparticles(PVP-Pt NPs),combined with a miniature pneumatic distance sensor,an instant detection method based on PVP-Pt NPs for high-sensitivity,fast and easy detection of H₂S was developed.H₂S can recognize and inhibit the catalytic activity of PVP-Pt NPs,which mimics catalase.After adding H₂O₂,the amount of O₂that is catalytically produced is significantly reduced,and the change in gas production leads to changes in the movement of the indicator dye.Under the best conditions,the designed miniature pneumatic distance sensor has good linearity in the concentration range of 1-50?M,and the detection limit is 0.17?M.At the same time,the recovery rate and RSD range of the actual sample addition are between 95.3%-99.0%and4.2%-5.9%,respectively.The results show that the miniature pneumatic distance sensor is suitable for the analysis and detection of actual samples.The method has the advantages of simplicity,rapidity,good portability,integration of detection and result output,etc.,and is suitable for on-site instant detection of food quality.