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The development of simple methods for the isolation and quantification of exosomes in biological samples is important. By using the typical two-dimensional (2D) nanomaterials, graphene oxide (GO), the present work first studied the interaction of liposomes with the nanocomposites formed by adsorbing HRP on the GO surface and found the presence of liposomes led to the release of HRP from the GO surface to the solution phase triggering the luminol-H 2 O 2 chemiluminescence (CL) reaction to emit light. Benefiting from the similarity of exosomes to liposomes in both composition and morphology aspects, the GO-HRP nanocomposites with a mass ratio of 120:1 and 160:1 were employed for the quantitative detection of exosomes in 100-fold diluted serum samples. The whole detection process took about 15 min and as low as 3.2 × 102 particles μL−1 of exosomes could be sensitively detected. In addition to GO-HRP nanocomposites, the CL responses of other nanocomposites obtained from adsorbing HRP on other 2D nanomaterials such as layered MoS 2 for exosomes were also tested. MoS 2 -HRP exhibited similar behavior and the LODs for the detection of exosomes were 5.8 × 102 particles μL−1. The proposed assays were a biomarker-independent quantitative method that achieved the quantification of exosomes in serum samples directly without an isolation process. [Display omitted] • A chemiluminescence method achieved rapid detection of exosomes based on 2D nanomaterial-enzyme composites. • The detection limit was as low as 3.2 × 102 particles μL−1 based on GO-HRP composites. • The detection limit was 5.8 × 102 particles μL−1 based on MoS 2 -HRP composites. • The assays achieved direct detection of exosomes in serum samples without isolation. [ABSTRACT FROM AUTHOR]

Healthcare-associated infections (HAIs) have increasingly become a threat to global health. Rapid, accurate, and reliable detection of HAI-related bacteria is urgently needed. Here, we presented a novel antimicrobial peptide-based surface-enhanced Raman scattering lateral flow assay (SERS-LFA) for the detection of multiple HAI-related bacteria. Antimicrobial peptide cecropin 1(CP1) was immobilized on the surface of Fe 3 O 4 @Au by the streptavidin-biotin system to capture Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli O157:H7 (E. coli O157:H7) simultaneously. The synthesized Fe 3 O 4 @Au-CP1 exhibits excellent broad-spectrum capturing ability, rapid magnetic enrichment function, and superior antibacterial activity. LFA strips enable the specific detection of two target bacteria in a quick and simple manner, with bacterial type differentiation via corresponding monoclonal antibodies sprayed. The highly sensitive SERS signals and the amplification effect of streptavidin-biotin significantly improved the sensitivity of detection. The LODs of P. aeruginosa and E. coli O157:H7 were 12 and 16 cells/mL, respectively. This assay also exhibited good specificity and reproducibility when applied to urine samples. Therefore, Fe 3 O 4 @Au-CP1-based SERS-LFA has great potential for detecting multiple bacteria after infection as well as regularly monitoring therapeutic efficacy. • CP1 was first utilized as a broad-spectrum recognition element in SERS-LFA to detect multiple bacteria simultaneously. • The amplification effect of the streptavidin-biotin system enhances the binding efficiency of Fe 3 O 4 @Au-CP1 to bacteria. • Fe 3 O 4 @Au-CP1 MNPs enable quick capture and enrichment of bacteria. • CP1-based SERS-LFA can achieve highly sensitive and quantitative detection for P. aeruginosa and E. coli O157:H7. • The LODs for P. aeruginosa and E. coli O157:H7 were 12 cells/mL and 16 cells/mL, respectively. [ABSTRACT FROM AUTHOR]

Obtaining lignin-based graphite-like microcrystallites at a relatively low carbonization temperature is still very challenging. In this work, we report a new method based on condensed structures, for regulating graphite-like microcrystalline structures via the incorporation of 4,4′-diphenylmethane diisocyanate (MDI) into the main structure of lignin. The effects of MDI on the thermal properties of lignin and the graphite-like microcrystalline structure of lignin-based ultrafine carbon fibers were extensively studied and investigated. The incorporation of MDI decreased the thermal stability of lignin, increased the carbon yield and enhanced the formation of graphite-like microcrystallites, which are beneficial for reducing energy consumption during the preparation of lignin-based carbon fibers. The modified lignin-based ultrafine carbon fibers (M-LCFs) demonstrated satisfactory electrochemical performance, including high specific capacitance, low charge transfer resistance, and good cycle performance. The M-LCFs-3/2 electrode had a specific capacitance of 241.3 F g−1 at a current density of 0.5 A g−1, and a residual ratio of 90.2 % after 2000 charge and discharge cycles. This study provides a new approach to control the graphite-like microcrystalline structure and electrochemical performance while also optimizing the temperature. • Lignin-based carbon fiber with graphite structure was prepared at a low temperature. • Condensed structure facilitate the formation of graphite-like structure. • MDI decreased the thermal stability of lignin and energy consumption of carbon fiber. • MDI-modified lignin shows fascinating application in supercapacitor. [ABSTRACT FROM AUTHOR]

Point-of-care quantitative analysis of tracing microRNA disease-biomarkers remains a great challenge in the clinical diagnosis. In this paper, we developed a portable fluorescent lateral flow assay for ultrasensitive quantified detection of acute myocardial infarction related microRNAs in bio-samples. SiO 2 @DQD (bilayer quantum dots assembly with SiO 2 core) based fluorescent lateral flow strip was fabricated as the analysis tool. In order to quantify the tracing microRNA in biosamples, a catalytic hairpin assembly and CRISPR/Cas12a cascade amplification method was performed and combined with the fabricated SiO 2 @DQD lateral flow strip. Thus, our platform gathered double advantages of portability and ultrasensitive quantification. Based on our strips, target myocardial biomarker microRNA-133a can be detected with a detection limit of 0.32 fM, which was almost 1000-fold sensitive compared with previous reported microRNAs-lateral flow strips. Significantly, this portable fluorescent strip can directly detect microRNAs in serum without any pretreatment and PCR amplification steps. When spiked in serum samples, a recovery of 99.65 %-102.38 % can be obtained. Therefore, our method offers a potential tool for ultrasensitive quantification of diseases related microRNA in the point-of-care diseases diagnosis field. [Display omitted] • Ultrasensitive single-line based SERS lateral flow assay for multiple exosomal proteins analysis has been developed. • For the first time CHA and CRISPR/Cas12a strategy were combined with LFA to improve the sensitivity. • The LOD (0.3 fM) was almost 1000-fold sensitivity than the previous fluorescence strips for miRNAs. • MiRNAs can be directly detected in serum without pretreatment or PCR amplification. • This assay possesses universality for miRNAs related diseases diagnosis in clinical setting. [ABSTRACT FROM AUTHOR]