Application Of Chalcogenide Copper Nanocrystals In Colorimetric Detection And Photothermal Therapy Of Cancer Cells

Cancer is the disease that seriously harms the health of human life.Its early diagnosis and effective treatment have been becoming an important task in the field of scientific research today.Detecting the number of cancer cells is one of the popular ways to prevent and diagnose the early malignant tumors.Multimode combining photothermal therapy is an important strategy for the treatment of cancer,especially the combination of chemotherapy and photothermal therapy.In recent years,the wide application of nanomaterials has been provided to be of great potential for the early diagnosis of cancer and multimode treatment.Chalcogenide copper nanocrystals?CuCNCs?is an important class of p-type semiconductor nanomaterials formed by the metal element Cu and chalcogen elements?such as S,Se,Te,etc.?.Due to their high carrier density,they exhibits the localized surface plasmon resonance?LSPR?properties in the near-infrared region and have high photothermal conversion efficiency.They can be used as the near-infrared optical probes and reagents for the diagnosis and treatment of cancer.There are many methods for preparing copper selenide nanocrystals.Due to their excellent bio-imaging properties and photothermal conversion effects,small-sized copper selenide nanocrytals have been received extensive attention.However,their synthesis generally adopts stringent conditions and environment?such as oil phase synthesis with high temperature or nitrogen protection.?,and their physical and chemical properties and the potential for the biological application have not been fully exploited,and there is still much room for expansion.Therefore,based on the optical properties of copper selenide nanomaterials,our work expands the application of CuCNCs in the detection and treatment of cancer cells.The contents are listed as follows,1.Cu_2-xSe/rGO used as a nanozyme in the colorimetric detection of the number of cancer cells.Cu_2-xSe nanoparticles were synthesized in situ using graphene solution?GO?,selenium dioxide?SeO₂?,coppersulfate?CuSO₄?5H₂O?as raw materials and ascorbic acid?VC?as reducing agent through a simple green one-step thermal synthesis method to obtain Cu_2-xSe/rGO complex.The compound showed nano-enzyme properties,which can synergistically catalyze H₂O₂ to produce hydroxyl radical,and oxidize 3,3',5,5'-tetramethylbenzidine?TMB?to show blue color with absorption peak at 652 nm.The nanozyme was used for direct colorimetric detection of cancer cells,in which folic acid was selected to target cancer cells overexpressing folate receptors.The selective binding of Cu_2-xSe/rGO with folic acid to cancer cells converted the catalytic process into quantitative colorimetric signals,and 63 cancer cells?MCF-7?can be distinguished by the naked eye.This strategy can be further used in the field of biological analysis.2.Cu_2-xS_ySe_1-y NPs used as drug carriers and photothermal reagents for chemotherapy-photothermal therapy for cancer cells.Dopamine?DA?and the anticancer drugs bortezomib?BTZ?can form stable,covalently bound inactive conjugates under neutral and alkaline conditions,but be decomposed under acidic conditions to release the active drugs BTZ.Cu_2-xS_ySe_1-y NPs coated with DA can form a complex Cu_2-xS_ySe_1-y@pDA.The complex is covalently bound to FA after loading BTZ to recognize the targeting cancer cells,and be decomposed under the acidic conditions of cancer tissues to release free BTZ drugs.Besides,the Cu_2-xS_ySe_1-y@pDA has a good photothermal treatment effect under the near-infrared II laser irradiation,so the anti-cancer effect of combining chemotherapy with photothermal therapy can be achieved.3.The systhesis of a small-sized,multi-functional copper selenide nanoprobe and investigation of its optical properties and cytotoxicity.In this experiment,ascorbic acid?VC?as a reducing agent,copper chloride?CuCl₂?2H₂O?and selenium dioxide?SeO₂?as the precursors were used,and polyvinylpyrrolidone?PVP?was applied as the surfactant.The luminescent Cu_2-xSe nanodots with small particle size were obtained by a simple one-step hydrothermal method at 90°C.The Cu_2-xSe nanodots had good photothermal conversion performance in the near-infrared region,and it also showed quantum fluorescence properties,peroxide mimic enzyme properties,and low cytotoxicity which showed promise for the next step in the detection and photothermal therapy of cancer by real-time fluorescence imaging analysis.In conclusion,the colorimetric detection and synergistic treatment of photothermal and chemotherapy for cancer cells have been realized based on the high carrier density and the local surface plasmon resonance?LSPR?properties of chalcogenide copper nanocrystals.Moreover,a luminescent copper selenide nanoprobe with small size,near-infrared absorbance and peroxide mimic enzyme properties has been synthesized,which was expected to be used for further detection,photothermal therapy and imaging analysis of cancer cell.