Urchin-like Na-doped zinc oxide nanoneedles for low-concentration and exclusive VOC detections

In the early-stage diagnosis of lung cancer,the low-concentration(<5 ppm)volatile organic compounds(VOCs)are extensively identified to be the biomarkers for breath analysis.Herein,the urchin-like sodium(Na)-doped zinc oxide(ZnO)nanoneedles were synthesized through a hydrothermal strategy with the addition of different contents of citric acid.The Na-doped ZnO gas sensor with a 3:1 molar ratio of Na^(+)and citric acid showed outstanding sensing properties with an optimal selectivity to various VOCs(formaldehyde(HCOH),isopropanol,acetone,and ammonia)based on working temperature regulation.Specifically,significantly enhanced sensitivity(21.3@5 ppm)compared with pristine ZnO(~7-fold),low limit of detection(LOD)(298 ppb),robust humidity resistance,and long-term stability of formaldehyde sensing performances were obtained,which can be attributed to the formation of a higher concentration of oxygen vacancies(20.98%)and the active electron transitions.Furthermore,the improved sensing mechanism was demonstrated by the exquisite band structure and introduction of the additional acceptor level,which resulted in the narrowed bandgap of ZnO.

A neutrophil-biomimic platform for eradicating metastatic breast cancer stem-like cells by redox microenvironment modulation and hypoxia-triggered differentiation therapy

Metastasis accounts for 90%of breast cancer deaths,where the lethality could be attributed to the poor drug accumulation at the metastatic loci.The tolerance to chemotherapy induced by breast cancer stem cells(BCSCs)and their particular redox microenvironment further aggravate the therapeutic dilemma.To be specific,therapy-resistant BCSCs can differentiate into heterogeneous tumor cells constantly,and simultaneously dynamic maintenance of redox homeostasis promote tumor cells to retro-differentiate into stem-like state in response to cytotoxic chemotherapy.Herein,we develop a specifically-designed biomimic platform employing neutrophil membrane as shell to inherit a neutrophil-like tumor-targeting capability,and anchored chemotherapeutic and BCSCs-differentiating reagents with nitroimidazole(NI)to yield two hypoxia-responsive prodrugs,which could be encapsulated into a polymeric nitroimidazole core.The platform can actively target the lung metastasis sites of triple negative breast cancer(TNBC),and release the escorted drugs upon being triggered by the hypoxia microenvironment.During the responsiveness,the differentiating agent could promote transferring BCSCs into non-BCSCs,and simultaneously the nitroimidazole moieties conjugated on the polymer and prodrugs could modulate the tumor microenvironment by depleting nicotinamide adenine dinucleotide phosphate hydrogen(NADPH)and amplifying intracellular oxidative stress to prevent tumor cells retro-differentiation into BCSCs.In combination,the BCSCs differentiation and tumor microenvironment modulation synergistically could enhance the chemotherapeutic cytotoxicity,and remarkably suppress tumor growth and lung metastasis.Hopefully,this work can provide a new insight in to comprehensively treat TNBC and lung metastasis using a versatile platform.

Metal oxide semiconductor gas sensing materials for early lung cancer diagnosis

The urgency of early lung cancer(LC)diagnosis and treatment has been more and more significant.Exhaled breath analysis using gas sensors is a promising way to find out if someone has LC due to its low-cost,non-invasive,and real-time monitoring compared with traditional invasive diagnostic techniques.Among sensor-based gas detection techniques,metal oxide semiconductor’s gas sensors are one of the most important types.This review presents the-state-of-art in metal oxide gas sensors for the diagnosis of early LC.First,the exhaled breath biomarkers are described with emphasis on the concentration of abnormal volatile organic compounds(VOCs)caused by the metabolic process of LC cells.Then,the research status of metal oxide gas sensors in LC diagnosis is summarized.The sensing performance and enhancement strategy of biomarkers provided by metal oxide semiconductor materials are reviewed.Another effective way to improve VOC detection performance is to build a gas sensor array.At the same time,various gas sensors combined with self-powered techniques are mentioned to display a broad development prospect in breath diagnosis.Finally,metal oxide gas sensor-based LC diagnosis is prospected.

Low concentration isopropanol gas sensing properties of Ag nanoparticles decorated In_(2)O_(3) hollow spheres

In order to detect low concentrations of volatile organic compounds (VOCs) for the early diagnosis of lung cancer, sensors based on hollow spheres of In_(2)O_(3) were prepared through the soft template method. Ag nanoparticle decorated In_(2)O_(3) composites were synthesized via dipping and annealing. The microstructure, phase composition, element distribution, and state of Ag were analyzed by the scanning electron microscopy (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The gas sensing tests showed that Ag-In_(2)O_(3) sensors had the highest response to isopropanol at 300 ℃. The best response of Ag-In_(2)O_(3) composite sensor was 5.2, which had a significant improvement compared with only In_(2)O_(3). Moreover, the response and recovery time of Ag-In_(2)O_(3) composite sensor was significantly shortened. The improved sensing properties of Ag-In_(2)O_(3) composite sensor could be attributed to the Schottky barrier created at Ag-In_(2)O_(3) interface and catalytical effect of Ag.