Analysis Of Relative Species In The Diseases Based On Surface-enhanced Raman Spectroscopy

Theranostics is a smart flagship in medicine,a synergistic system with simultaneous therapeutic and diagnostic competencies.Ideally,an effective theranostic probe should fulfill the following two criteria:?i?ideal to target the endogenous cancer markers to offer the accurate control and?ii?possessing both high detection sensitivity and therapeutic potency.However,so far it still remains challenging to engineer a single theranostic probe to possess all these characteristics.Alzheimer's disease is one of the neurodegenerative diseases.Tens of millions of patients worldwide have been affected by Alzheimer's disease.Surveys have shown that about 60%of neurons in the brain of most AD patients have been damaged when they seek medical advice.Therefore,the early diagnosis of Alzheimer's disease is of great significance for the later treatment.This paper has carried out in-depth exploration and research on the above-mentioned two aspects.In the first work,we created a multifunctional ratiometric integrated theranostic nanoplatform,in which copper?II?phthalocyanine?CuPc?molecule played double key roles in PDT as well as in situ SERS monitoring and imaging capability.On one hand,due to the high enhanced factor?EF?value of SERS signals for CuPc on hexagonal boron nitride nanosheets?h-BNNS?,the amplification strategy specifically designed by hairpin G-quadruplex?HG?DNA,and the ratiometric determination with built-in corrections for avoiding environmental effects,CuPc was first used as a sensitive and accurate diagnostic sounder for hsa-miR-21?miR-21?monitoring and imaging with limit of detection?LOD?down to 0.70 fM in cell lysis.CuPc intercalated into HG DNA improved its solubility to act as an effective PS for PDT.Here,miR-21 was chosen as target miRNA for its significant elevated content in a variety of cancers as reported previously,especially in breast cancer?BC?.Real-time monitoring of miR-21 with our developed ultrasensitive and high selective theranostic nanoplatform guided the early theranostics to improve the therapy efficiency of BC.In the early stage of tumor,low dosesof drug?CuPc@HG@BN?completely eliminated the tumor only for 3 days.As for the late stage,4 times dose of drug still exhibited an effective inhibition for the tumor.Both in vitro and in vivo data demonstrated that the integrated nanoplatform showed remarkable enhancement in PDT efficiency with minimized damage to the normal tissues.In the second work,we developed a template method to study the aggregation process of A?₄₀ according to the characteristics of protein.Various morphologies of A?₄₀ were observed by atomic force microscopy?AFM?,and gold nanoparticles with different morphologies were synthesized using A?₄₀ as templates.We found that gold nanoparticles synthesized with different morphologies of A?₄₀ have different surface enhanced Raman scattering?SERS?effects.We explained the reasons for the different SERS effects by studying the changes of zeta potential and morphological characteristics during the aggregation of A?₄₀.In addition,we studied the effect of three high concentration of metal ions(Cu²⁺,Zn²⁺,Fe³⁺)on the aggregation of A?₄₀ by surface enhanced Raman scattering?SERS?.Furthermore,we have realized the direct selective SERS detection of A?₄₀ by template method.