Construction Of Light-controlled Device For The Diagnosis Of Infectious Diseases

Cancer is one of the most serious chronic diseases with high morbidity and mortality.Currently,the most common treatments for cancer are radiotherapy and chemotherapy,which can inhibit malignant tumor metastasis to a certain extent.These clinic methods inevitably eliminate lymphocytes at the time for killing tumor cells,leading to a decrease in immunity and triggering serious whole-body bacterial infections.Bacterial infections reversely cause inflammation or release genetic toxins,significantly suppressing the immune cell-based immunity and consequently accelerating the metastasis of tumor cells.Clinically,broad-spectrum antibiotic therapy is the commonly applied therapeutic strategy,while the empirical broad-spectrum antibiotic therapy causes the destruction of microflora balance and the emergence of antibiotic-resistant bacteria.At the early stages of infection,the concentration of bacteria in the blood is extremely low.Therefore,targeted capture of trace infectious bacteria in blood and isolation of bacteria for downstream drug resistance analysis is of great significance for specific antibiotic treatment of bacterial infections.The emerged functionalized device can capture trace bacteria in blood with high sensitivity and specificity,which brings hope for the detection and treatment of bacterial infection.Currently,functionalized devices based on Si nanowire arrays,polycrystalline Ni Co₂O₄ nanowires,graphene/silver/silicon sandwich structure,and silver nanoparticles/silicon nanostructure have been utilized to enrich and analyze trace bacteria in the blood.However,these functionalized devices are hindered by the ability to release bacteria for downstream genetic analysis.Hence,the construction of reliable functionalized devices to efficiently capture and control the release of bacteria in the blood is desirable for the targeted treatment of bacterial infections.In this paper,we construct a NIR light-responsive device that is based on aptamer modified black phosphorus nanostructure（BP/Apt）for specific capture and controlled release of trace bacteria in serum for downstream genetic analysis.The details are as follows:（1）Two-dimensional BP nanosheets were obtained by solvent exfoliation approach.The Apt/BP device constructed by the drop-casting method was composed of aptamer functionalized BP nanosheets.BP nanosheets showed excellent NIR photothermal conversion efficiency,biocompatibility and biodegradability.Stacked BP nanostructures with high specific surface areas could effectively increase the binding sites through interfacial topographical interaction.Aptamers with specific targeting ability could efficiently release captured bacteria due to the conformation change upon light triggering.（2）The capture and light controlled release efficiency of the BP/Apt device for two kinds of bacteria were explored.Our designed BP/Apt device with high sensitivity and specificity has realized the targeted capture of pathogenic bacteria in human serum samples,as well as a light-controlled release for the downstream drug resistance analysis,guiding the diagnosis of bacterial infectious diseases and personalized medicine.