Combined Tlc-sers For The Rapid Detection Of Adulterated Biguanides And Thiazolidinediones Hypoglycemic Drugs In Chinese Traditional Patent Medicines

Objective:In this paper,the doping detection of hypoglycemic drugs is the target,and the surface enhanced Raman scattering（SERS）detection technology is selected.Firstly,a series of silver coated gold nano cubes are synthesized（Au@Ag NCs）active substrate,and through morphology characterization and performance screening,the best substrate material is selected.Then,the sensitivity and repeatability of the control solution of each hypoglycemic agent were tested using the selected substrate,The antidiabetic drugs adulterated in traditional Chinese patent medicines and simple preparations were detected.Finally,by combining SERS with Thin Layer Chromatography（TLC）and optimizing the development conditions,the goal of simultaneous detection of four doped hypoglycemic drugs was ultimately achieved.It is hoped to provide a faster,more economical,and more convenient method for doping detection of hypoglycemic drugs.Method:（1）A nano substrate with high SERS activity was prepared.Preparation of gold nano cubes（Au NCs）by small gold octahedral seed mediated method,First,using Na BH₄to reduce HAu Cl₄to obtain a gold nano seed solution,then using ascorbic acid to reduce HAu Cl₄to obtain a small gold octahedral seed solution,and then further growing to obtain Au NCs.Finally,in order to obtain high yield Au NCs,flocculation and purification were performed on them.TEM,UV-vis,particle size analysis,etc.were used for characterization.Then,in Au NCs solution,different amounts of silver nitrate are reduced using ascorbic acid at 60℃to obtain silver with different thicknesses Au@Ag NCs.The morphology was also characterized by TEM,HRTEM,UV-vis,and particle size analysis;Using crystal violet（CV）molecules with high SERS activity as the object to be measured Au@Ag NCs Performance.（2）Using commonly doped biguanides（phenformin hydrochloride,metformin hydrochloride）and thiazolidinediones（pioglitazone hydrochloride,rosiglitazone maleate）as test objects Au@Ag NCs serve as SERS substrates.The sensitivity and repeatability of SERS were tested for the reference solutions of these four hypoglycemic drugs.Finally,four antidiabetic drugs were added to traditional Chinese patent medicines and simple preparations to make a simulated positive sample,and their sensitivity was also investigated and tested.（3）Although SERS detection has the advantages of high sensitivity,good repeatability,low detection cost,and fast speed,it lacks specificity and selectivity.Therefore,it can be combined with TLC separation technology to achieve simultaneous detection of these four hypoglycemic drugs in a short time.Firstly,the development system was selected,and then the proportion of the development agent was further optimized to enable the full separation of the four hypoglycemic drugs.Finally,Au@Ag NCs substrate drops onto the spots of the thin layer plate for Raman detection.Result:（1）Through the characterization of Au NCs by TEM and particle size analysis,it can be found that we have successfully synthesized Au NCs of about 54 nm.Its side length presents a normal distribution and a narrow distribution.Combined with the single peak of UV-vis at 400-500 nm,it indicates that the morphology and size of the synthesized Au NCs are relatively uniform.Further synthesized Au@Ag NCs With silver shell thicknesses of 7 nm,12 nm,16 nm and 18.5 nm,respectively.After Raman testing of10^-6M CV molecules,it was found that the highest SERS activity was found in silver with a thickness of 16 nm Au@Ag NCs.（2）Use the selected ones with the best SERS activity Au@Ag NCs as a substrate can detect concentrations of phenformin hydrochloride,metformin hydrochloride,pioglitazone hydrochloride,and rosiglitazone maleate control samples,respectively 0.2μg/m L,1μg/m L,0.25μg/m L,1μg/m L.And as the concentration of hypoglycemic drugs decreases,the corresponding Raman peak intensity also decreases.The antidiabetic drugs doped into traditional Chinese patent medicines and simple preparations can be detected by 0.05μg/mg,0.5μg/mg,0.05μg/mg,0.5μg/mg.This method can meet the requirements for doping detection of these drugs by comparing them with the minimum effective amounts of these four drugs.（3）We used TLC combined with SERS technology for drug doping detection.The optimal development system for the four drugs is n-butanol:glacial acetic acid:methanol,and the optimal development ratio is 11:2:3.Under this development condition,the specific shifts of the four drugs are 0.130,0.283,0.478 and 0.804,respectively,which can be well separated.Combined with SERS technology,the simultaneous detection of four drugs in a short time was achieved.Conclusion:In this paper,we first prepared a core-shell structure Au@Ag NCs substrates were then characterized by morphology and compared with SERS properties to select the optimal substrate.Then,using this substrate,the independent detection of control samples and simulated positive samples of biguanides（phenformin hydrochloride,metformin hydrochloride）and thiazolidinediones（pioglitazone hydrochloride,rosiglitazone maleate）hypoglycemic drugs was realized.Finally,TLC was used to optimize the deployment conditions to achieve the separation of four drugs,followed by SERS detection,ultimately achieving simultaneous detection of the four drugs in a short period of time.Compared to other doping detection technologies,this method has low cost,fast response speed,and high selectivity,providing application potential for drug doping detection in actual samples.