Study On Preparation And Application Of Green Synthetic Noble Metal Nanoparticles By Lilium Casa Blanca Biomass

Noble metal nanoparticles are widely used in biopharmaceuticals,sensors,optical microscopy,anti-oxidation,catalysis,food testing,etc.due to their unique physical and chemical properties.Silver nanoparticles（AgNPs）and gold nanoparticles（AuNPs）are the most studied noble metal nanoparticles.In this paper,AgNPs and AuNPs were successfully synthesized by using a wide range of Lilium casa blanca.AgNPs and AuNPs were characterized by modern analytical technology.The stability,antioxidation,and application of AgNPs and AuNPs were studied.The relationship between the shape and size of green synthetic AuNPs and reaction conditions were preliminarily investigated.The main test results are as follows:（1）Study on the preparation and Raman spectra application of the green synthetic AgNPs using Lilium casa blanca biomass:When the total volume of system was 25 mL,material ratio of Lilium casa blanca powders to silver nitrate solution was 2:1,pH value of solution was 12,reaction temperature was 37°C,and heating time was 12 h,the green synthetic AgNPs which functional groups,such as amines,alcohols,ketones,aldehydes,hydroxyl groups and carboxylic acids were attached to the surface were spherical,and had good dispersibility.The characteristic absorption peak of AgNPs which average particle size was 5.591±1.518 nm was at 410 nm,and the conversion rate was reached to 98.304%.AgNPs had good stability,oxidation resistance,and surface-enhanced Raman（SERS）activity.The Raman enhancement factor was 1.676×10³ with AgNPs were used as Raman enhanced substrate and 2-mercaptopyridine was used as the probe molecule.When the total volume of system was 1 mL,the concentration of AgNPs was 106.04μg/mL,and the volume ratio of AgNPs to amoxicillin standard solution was 4:1,the concentration of amoxicillin standard solution had a good linear relationship with its peak strength at 1055cm^-11 in the range of 1¹000μg/mL.The minimum detection limit was 1μg/mL.The recovery of method was 84.51⁹3.62%,and the relative standard deviation was 5.16%.（2）Study on the preparation and catalytic application of the green synthetic AuNPs using Lilium casa blanca biomass:When the total volume of system was 25 mL,material ratio of Lilium casa blanca powders to hydrocholoroauric acid solution was 3:1,pH value of solution was 10,reaction temperature was 80°C,and heating time was 30 min,the green synthetic AuNPs which functional groups,such as amines,alcohols,ketones,aldehydes,hydroxyl groups and carboxylic acids were attached to the surface were spherical,and had good dispersibility.The characteristic absorption peak of AuNPs which average particle size was 5.933±1.158 nm was at 532 nm,and the conversion rate was reached to 99.997%.AuNPs had good stability,oxidation resistance,and catalytic activity.AuNPs were used as catalysts to catalyze the reduction reaction of p-nitrophenol,m-nitrophenol,o-nitrophenol and methylene blue.The corresponding normalized reaction rates were 26.610、95.950、23.410 mM^-11 min^-11 and 0.448 M^-11 min^-1,respectively.Compared with other literatures,the normalized reaction rate of our AuNPs to catalyze p-nitrophenol was higher.（3）Study on the SERS activity of the green synthetic AuNPs under different reaction conditions:AuNPs of different shapes and sizes were synthesized by controlling the pH of solution and material ratio.In the green synthesis of AuNPs,flavonoids and polyphenols were responsible for reduction;sugars and proteins were responsible for stabilization.The results of high-resolution transmission electron microscopy showed that alkaline environment was favorable for the formation of spherical AuNPs with smaller particle size,and the acidic environment was more favorable for the formation of AuNPs with larger particle size and various shapes.The SERS activity was investigated with the AuNPs which synthesized at different reaction conditions were used as Raman enhanced substrate and 2-mercaptopyridine was used as the probe molecule.The results showed that the AuNPs synthesized under acidic conditions had strong SERS activity.When the amount of Lilium casa blanca powders was 30 mg and pH of solution was 2,the biosynthesis AuNPs had the highest SERS activity,and the Raman enhancement factor was 5.605×10³.