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The peroxidase (POD)‐mimic nanozymes can be a potential tool for point‐of‐care (POC) diseases diagnosis. However, the complex sample matrix and unspecific multiple‐enzyme activities of nanozyme can generate false background signal and decrease the diagnostic accuracy. Here, a magnetic and POD‐specific covalent organic framework (COF) confined osmium (Os) nanoclusterzyme Fe3O4@COF@Os is developed for biomarkers biosensing. First, found that the catalytic activity and specificity of Fe3O4@COF@Os can be regulated by the deoxidizers and the functional groups of COF ligands. By using ascorbic acid as deoxidizer and F functional COF ligands, Fe3O4@COF@Os displayed superior POD‐specific activity and negligible oxidase (OXD) and catalase (CAT) mimic activity. Therefore, Fe3O4@COF@Os can separate and analyze of targets in bio‐matrix without background interference. For application, Fe3O4@COF@Os based lateral flow assay is established for serum cancer biomarker prostate‐specific antigen, the detection limit is 3.83 pg mL−1. For clinical prostatic cancer samples, the accuracy is 100% with a correlation coefficient of 0.998 with commercial ELISA kit. For chronic disease biomarker sensing, salivary glucose can be quantified as low as 0.1 µm, with negligible background interference and favorable recyclability. This specific magnetic nanozymes can offer a promising pretreatment‐free and POC strategy for rapid and accurate diseases diagnosis. [ABSTRACT FROM AUTHOR]

A correction to the article regarding nanoparticles-based metal-enhanced fluorescent (MEF) aptasensor that was published in the 2015 issue is presented.

A correction to the article regarding nanoparticles-based metal-enhanced fluorescent (MEF) aptasensor that was published in the 2015 issue is presented.

A turn on and label-free fluorescent apasensor for Hg2+ with high sensitivity and selectivity has been demonstrated in this report. Firstly, core−shell Ag@SiO2 nanoparticles (NPs) were synthetized as a Metal-Enhanced Fluorescent (MEF) substrate, T-rich DNA aptamers were immobilized on the surface of Ag@SiO2 NPs and thiazole orange (TO) was selected as fluorescent reporter. After Hg2+ was added to the aptamer-Ag@SiO2 NPs and TO mixture buffer solution, the aptamer strand can bind Hg2+ to form T-Hg2+-T complex with a hairpin structure which TO can insert into. When clamped by the nucleic acid bases, the fluorescence quanta yield of TO will be increased under laser excitation and emitted a fluorescence emission. Furthermore, the fluorescence emission can be amplified largely by the MEF effect of the Ag@SiO2 NPs. The whole experiment can be finished within 30 min and the limit of detection is 0.33 nM even with interference by high concentrations of other metal ions. Finally, the sensor was applied for detecting Hg2+ in different real water samples with satisfying recoveries over 94%. [ABSTRACT FROM AUTHOR]

A turn on and label-free fluorescent apasensor for Hg2+ with high sensitivity and selectivity has been demonstrated in this report. Firstly, core−shell Ag@SiO2 nanoparticles (NPs) were synthetized as a Metal-Enhanced Fluorescent (MEF) substrate, T-rich DNA aptamers were immobilized on the surface of Ag@SiO2 NPs and thiazole orange (TO) was selected as fluorescent reporter. After Hg2+ was added to the aptamer-Ag@SiO2 NPs and TO mixture buffer solution, the aptamer strand can bind Hg2+ to form T-Hg2+-T complex with a hairpin structure which TO can insert into. When clamped by the nucleic acid bases, the fluorescence quanta yield of TO will be increased under laser excitation and emitted a fluorescence emission. Furthermore, the fluorescence emission can be amplified largely by the MEF effect of the Ag@SiO2 NPs. The whole experiment can be finished within 30 min and the limit of detection is 0.33 nM even with interference by high concentrations of other metal ions. Finally, the sensor was applied for detecting Hg2+ in different real water samples with satisfying recoveries over 94%. [ABSTRACT FROM AUTHOR]

Limited by the insufficient catalytic substrates such as H 2 O 2 and O 2 in the tumor microenvironment (TME), the continual propelling of nanozymes catalysis therapy of cancer remains a challenge. Here, an all-in-one MnO 2 @PtAuRu nanoreactor is constructed for self-propelled and cascade catalytic therapy of tumors. The MnO 2 @PtAuRu is constructed by using hollow MnO 2 (≈150 nm) as the core-carrier and ultrasmall PtAuRu nanoclusters (≈2 nm) anchoring on the surface MnO 2 . According to the glucose oxidase (GOD)/catalase (CAT)/peroxidase (POD) mimic multienzyme activity of PtAuRu nanoclusters, cascaded nanocatalytic reactions can be self-replenishing to persistently produce •OH for superior chemodynamic therapy (CDT). Additionally, the MnO 2 carrier can protect the ultrasmall PtAuRu nanoclusters during the circulation and the overexpressed glutathione (GSH) in the tumor can also be degraded by the MnO 2 to synergy the CDT. The MnO 2 @PtAuRu displays obvious photothermal properties which further enhance the cascade catalytic ability and synergistic therapeutic effect. Therefore, this all-in-one nanozyme provides a promising strategy for the rational design of self-replenishment and self-replenishing cascade catalytic therapy of cancer., (© 2024 Wiley‐VCH GmbH.)

Exosomal microRNAs (miRNAs) have been proved to be important biomarkers for the early diagnosis of cancers. However, the accurate quantification of exosomal miRNAs is hampered either by laborious exosome isolation and lysis or by RNA extraction and the amplification process. Here, we reported an in situ platform for direct exosomal miRNAs from serum samples. First, locked nucleic acid (LNA)-modified Au@DTNB (DTNB is the Raman reporter molecule 5,5'-dithiobis-(2-nitrobenzoic acid)) was synthesized as surface-enhanced Raman scattering (SERS) tags to enter into exosomes and assemble with target miRNAs to induce hot-spot SERS signals. Second, Fe 3 O 4 @TiO 2 nanoparticles were added to enrich the exosomes through affinity interaction of the TiO 2 shell for further SERS detection. Based on the platform, target miRNAs can be directly qualified in situ with a detection limit of 0.21 fM, which is better or comparable with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and other in situ methods reported before. Moreover, neither capture antibody nor ultracentrifugation pretreatment was needed in the whole detection procedure. Using exosomal miRNA-10b as a proof of concept, pancreatic ductal adenocarcinoma (PDAC) patients can be recognized from normal controls (NCs) with an accuracy of 99.6%. The simple and sensitive in situ exosomal miRNA detection assay can be seen as a noninvasive liquid biopsy assay for clinical cancer diagnostic adaption.

The detection of hepatocellular carcinoma (HCC) circulating tumor cells (CTCs) from a blood sample can be a very powerful noninvasive approach for the early detection and therapy of liver cancer. However, the extreme rarity of tumor cells in blood containing billions of other cells makes the capture and identification of CTCs with sufficient sensitivity and specificity a real challenge. Here, a magnetically assisted surface-enhanced Raman scattering (SERS) biosensor for HCC CTC detection is reported for the first time. The biosensor consists of two basic elements: anti-ASGPR antibody-Fe 3 O 4 @Ag magnetic nanoparticles and anti-GPC3 antibody-Au@Ag@DTNB nanorods. According to the dual-selectivity of the anti-ASGPR and anti-GPC3 antibodies and the dual-enhancement SERS signal of the MNPs silver shell and the Au@Ag NRs SERS tags, a limit of detection of 1 cell mL -1 for HCC CTC in human peripheral blood samples with a linear relationship from 1 to 100 cells mL -1 can be obtained. The system shows good performance in real serum, which suggests it may be a promising tool for HCC clinical diagnosis., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)