Microtrace Detection Of Archaeological Silk Based On Photo/electrochemical Immunosensing Technology

Ancient silk has important historical,artistic,and scientific value.The study of silk relics can not only carry forward Chinese culture,but also promote international exchanges and cooperation and contribute to the development of human civilization.The origin and spread of silk have been hotly debated in the field of archaeology.The key to solve this dispute is to find the evidence of archaeological silk.However,traditional analytical methods have encountered great challenges in the analysis of archaeological silk microtraces due to the problems of large sample consumption,serious contamination,and degradation.Therefore,a super sensitive detection method for archaeological silk is urgently needed to improve the efficiency and accuracy of analysis.In this paper,using Bombyx mori silk fibroin as a immunogen to prepare monoclonal antibodies for species identification,the label-free photo/electrochemical immunosensors for the detection and identification of modern silk and archaeological silk samples were constructed.The specific research contents are shown as follows:1)A photoelectrochemical immunosensor for the microtrace detection of archaeological silk.A taxonomically specific anti-fibroin monoclonal antibody（anti-SF）was designed and successfully prepared by animal immunization,and a novel photoelectrochemical immunosensor based on cadmium sulfide quantum dots and silver nanoparticles co-sensitized zinc oxide nanowires array（Zn O NWA）was constructed for the first time.This photoelectrochemical immunosensor possessed a detection limit as low as 0.56 ng m L^-1and a linear range of 1～1000 ng m L^-1,showing great potential in the ultrasensitive detection of silk microtrace.In addition,the elaborate immunosensor demonstrated preeminent performances in the specificity,stability,and reproducibility,especially in the qualitative and quantitative detection of soil samples extracted from Sanxingdui archeological sites.Therefore,the proposed method not only verifies the accuracy and validity of the photoelectrochemical immunosensor but also provides a reference for the study of other types of protein artifacts.2)A MXene-based electrochemical immunosensor for the detection and species identification of archaeological silk microtraces.The anti-SF was successfully prepared using Bombyx mori silk as immunogen and a novel electrochemical immunosensor was proposed.Ti₃C₂T_x-MXene was anchored onto activated carbon cloth（ACC）to fabricate a nanoplatform,and anti-SF was subsequently introduced to complete the nanobioplatform.The specific capacitance of the ACC/Ti₃C₂T_x-MXene reached 892.5m F cm^-2at a current density of 1 m A cm^-2,showing high electrochemical performance.Moreover,the immunosensor possessed a broad linear range of 10^-2～10³ng m L^-1and a detection limit of 2.15 pg m L^-1.Subsequently,the qualitative and quantitative performance of the immunosensor was excellent in the analysis of archaeological samples.Therefore,this work demonstrates that the proposed method not only validates the accuracy and validity of the electrochemical immunosensor results,but also adds to our understanding of the role of emerging materials such as Ti₃C₂T_x-MXene in the design of novel biosensors.3)A dual-light responsive PEC immunosensor for archaeological silk microtrace detection based on Zn O-MX/Ag₂S sensitized structure.An elaborate visible/near-infrared（vis/NIR）photoelectrochemical（PEC）immunosensor was proposed,which employed Ag₂S nanoparticles（NPs）grown in situ on Zn O NWA-MXene nanocomposites（Zn O-MX）via ultrasonic method as photosensitive material.Experimental results illustrated that Zn O-MX/Ag₂S-based sensor could present more than 6.8 times PEC response than that of the Zn O-MX-based one under visible light illumination and the PEC signal of the Zn O-MX/Ag₂S nanocomposites was30 times as high as that of the Zn O-MX under 808 nm NIR light,respectively,indicating enhanced photoelectric activity of Zn O by Ti₃C₂T_x-MXene and Ag₂S and the matched energy band structure.Under optimal conditions,this PEC immunosensor presents high sensitivity and detection limit of 1.51 pg m L^-1.In addition,the immunosensor demonstrated preeminent performances in the specificity,stability,and reproducibility.Based on the above advantages,it is concluded that Zn O-MX/Ag₂S nanocomposites are potentially promising photoactive materials for applications in vis/NIR PEC immunosensors.