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Abstract High‐coverage mass spectrometry analysis of single‐cell metabolomics remains challenging due to the extremely low abundance and wide polarity of metabolites and ultra‐small volume in single cells. Herein, a novel concentric hybrid ionization source, nanoelectrospray ionization‐atmospheric pressure chemical ionization (nanoESI‐APCI), is ingeniously designed to detect polar and nonpolar metabolites simultaneously in single cells. The source is constructed by inserting a pulled glass capillary coaxially into a glass tube that acts as a dielectric barrier layer. Benefitting from the integrated advantages of nanoESI and APCI, its limit of detection is improved by one order of magnitude to 10 pg mL−1. After the operational parameter optimization, 254 metabolites detected in nanoESI‐APCI are tentatively identified from a single cell, and 82 more than those in nanoESI. The developed nanoESI‐APCI is successively applied to study the metabolic heterogeneity of human hepatocellular carcinoma tissue microenvironment united with laser capture microdissection (LCM), the discrimination of cancer cell types and subtypes, the metabolic perturbations to glucose starvation in MCF7 cells and the metabolic regulation of cancer stem cells. These results demonstrated that the nanoESI‐APCI not only opens a new avenue for high‐coverage and high‐sensitivity metabolomics analysis of single cell, but also facilitates spatially resolved metabolomics study coupled with LCM.

Abstract Single‐stranded DNA oligonucleotides wrapping on the surface of single‐walled carbon nanotubes (SWCNTs), described as DNA corona, are often used as a dispersing agent for SWCNTs. The uneven distribution of DNA corona along SWCNTs is related to the photoelectric properties and the surface activity of SWCNTs. An ionic strength‐mediated “DNA corona defects” (DCDs) strategy is proposed to acquire an exposed surface of SWCNTs (accessible surface) as large as possible while maintaining good dispersibility via modulating the conformation of DNA corona. By adjusting the solution ionic strength, the DNA corona phase transitioned from an even‐distributed and loose conformation to a locally compact conformation. The resulting enlarged exposed surface of SWCNTs is called DCDs, which provide active sites for molecular adsorption. This strategy is applied for the arrangement of SWCNTs on DNA origami. SWCNTs with ≈11 nm DCD, providing enough space for the adsorption of “capture ssDNA” (≈7 nm width required for 24‐nt) extended from DNA origami structures are fabricated. The DCD strategy has potential applications in SWCNT‐based optoelectronic devices.

Abstract In this manuscript, a simple method combining atomic layer deposition and magnetron sputtering is developed to fabricate high‐performance Pd/SnO2 film patterns applied for micro‐electro‐mechanical systems (MEMS) H2 sensing chips. SnO2 film is first accurately deposited in the central areas of MEMS micro hotplate arrays by a mask‐assistant method, leading the patterns with wafer‐level high consistency in thickness. The grain size and density of Pd nanoparticles modified on the surface of the SnO2 film are further regulated to obtain an optimized sensing performance. The resulting MEMS H2 sensing chips show a wide detection range from 0.5 to 500 ppm, high resolution, and good repeatability. Based on the experiments and density functional theory calculations, a sensing enhancement mechanism is also proposed: a certain amount of Pd nanoparticles modified on the SnO2 surface could bring stronger H2 adsorption followed by dissociation, diffusion, and reaction with surface adsorbed oxygen species. Obviously, the method provided here is quite simple and effective for the manufacturing of MEMS H2 sensing chips with high consistency and optimized performance, which may also find broad applications in other MEMS chip technologies.

Abstract Glioblastoma (GBM) is the most aggressive tumor of the central nervous system and remains universally lethal due to lack of effective treatment options and their inefficient delivery to the brain. Here the development of multifunctional polymeric nanoparticles (NPs) for effective treatment of GBM is reported. The NPs are synthesized using a novel glutathione (GSH)‐reactive poly (2,2″‐thiodiethylene 3,3″‐dithiodipropionate) (PTD) polymer and engineered for brain penetration through neutrophil elastase‐triggered shrinkability, iRGD‐mediated targeted delivery, and lexiscan‐induced autocatalysis. It is found that the resulting lexiscan‐loaded, iRGD‐conjugated, shrinkable PTD NPs, or LiPTD NPs, efficiently penetrate brain tumors with high specificity after intravenous administration. Furthermore, it is demonstrated that LiPTD NPs are capable of efficient encapsulation and delivery of chemotherapy doxorubicin and sonosensitizer chlorin e6 to achieve combined chemotherapy and sonodynamic therapy (SDT). It is demonstrated that the capability of GSH depletion of LiPTD NPs further augments the tumor cell killing effect triggered by SDT. As a result, treatment with LiPTD NPs effectively inhibits tumor growth and prolongs the survival of tumor‐bearing mice. This study may suggest a potential new approach for effective GBM treatment.

Abstract Diabetic retinopathy (DR) is the main cause of vision loss or blindness in working age adults worldwide. The lack of effective diagnostic biomarkers for DR leads to unsatisfactory curative treatments. To define potential metabolite biomarkers for DR diagnosis, a multiplatform‐based metabolomics study is performed. In this study, a total of 905 subjects with diabetes without DR (NDR) and with DR at different clinical stages are recruited. Multiplatform metabolomics methods are used to characterize the serum metabolic profiles and to screen and validate the DR biomarkers. Based on the criteria p