Design And Application Of New Anti-counterfeiting Fabric Label Based On SERS Label

Counterfeiting has caused a major blow to the global economy.In order to overcome the shortcomings of traditional anti-counterfeiting methods,surface enhanced Raman scattering(SERS)technology has been gradually introduced into anticounterfeiting applications in recent years.SERS technology can provide highly specific identification information corresponding to the substances on the surface of noble metal nanoparticles,which has great value and potential as anti-counterfeiting application.In this paper,gold nanorods(AuNRs)with different aspect ratios were prepared firstly by seed-growth method.Three kinds of Raman reporters(DTNB,4-MBA,MMTA)and four kinds of dye reporters(crystal violet,malachite green,rhodamine B,methylene blue)were attached to the surface of gold rods separately or simultaneously and coated with gold shells to obtain double-layer core-shell gold nanorods with nanogap(Au@AuNRs).The core-shell structure can not only significantly enhance the SERS signal of reporter molecule inside the gap,but also can ensure it will not be disturbed by the environment,so as to improve the signal stability and reproducibility of anti-counterfeiting information.Au@AuNRs with single-component or multicomponent reporter molecules inside the core-shell nanogap is called SERS tag.Further,Au@AuNRs solutions with single-component reporter molecules are mutually compounded and self-assembled to obtain the SERS tag compound gold nanofilm,and Au@AuNRs solution with multi-component reporter molecules is directly performed self-assembly to obtain multiple SERS tags gold nanofilm.The gold film with large area and easy to transfer is closer to the actual application scenarios,and the SERS information comes from the reporter molecules in the core-shell gap.The SERS tag assembled gold film not only has excellent SERS effect and unique SERS signal,but the characteristic peak position and peak intensity of the obtained SERS spectrum will also show up regular change with the change of the type and proportion of the reporter molecules used in the mixing process.Based on this regular change,a joint and transformation encoding method of SERS spectral wavenumber-intensity was created,the coding result of the SERS spectrum can be directly or combined with gold film for anti-counterfeiting,and the selection of reporters and characteristic peaks and the change of coding rules in any step can greatly increase the capacity of anticounterfeiting coding.Only a small amount of Raman reporters can create a large number of anti-counterfeiting SERS labels with extremely high identification accuracy and non-reproducibility.The dip coating method was used to finish the SERS tag assembled gold film on different fabrics(woven cotton,knitted cotton,wool,silk,polyester cotton),supplemented with polydimethylsiloxane(PDMS)film coating,this method not only has universality,can be widely applied to a variety of fabrics,but also can draw a certain pattern during the dip coating process to give the constructed anti-counterfeit fabric a certain aesthetic.In addition,while the anti-counterfeiting label retain the specific SERS anti-counterfeiting information of the gold film,the finishing of gold film can improve the anti-ultraviolet performance of the fabric,and the coating of PDMS film can bring good water repellency to the fabric.