Nanozyme-Inhibited SERS Multichannel Paper-Based Sensor Array for the Quantification and Identification of Biothiols and Cancer Cells Based on Three Ag-Based Nanomaterials.

Biothiols play essential roles in maintaining normal physiological functions, resisting oxidative stress, and protecting cell health. Establishing an effective and reliable sensor array for the accurate quantification and discrimination of diverse biothiols is extremely meaningful. In this work, Ag/Mn3O4, Ag3PO4, and Ag3Cit with excellent oxidase-mimetic activity and surface-enhanced Raman scattering (SERS)-enhanced features have been prepared and loaded onto Whatman filter paper (WFP) to build SERS paper chips as three sensing channels, which can induce 3,3',5,5'-tetramethylbenzidine (TMB) oxidation to SERS-active reporters (TMBox) and concurrently generate prominent SERS signals. Nevertheless, the addition of biothiols can suppress conversion from TMB to TMBox, which can cause the reduction of the SERS signal from TMBox. Interestingly, each SERS sensing channel can generate different TMBox signals' variations due to differences in the oxidative inhibition abilities of diverse biothiols and exclusive properties of each paper chip, which can be plotted as specific fingerprint patterns of each biothiol and further translated into intuitive two-dimensional (2D) clustering profiles through linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA) techniques for precise identification of these six biothiols with the minimum concentration of 1 µM. More importantly, this SERS sensor array is exploited for the precise quantification of intracellular glutathione (GSH), and can differentiate between normal and cancer cells based on different intracellular GSH contents and even identify different types of tumor cells, demonstrating its powerful application prospects in disease diagnosis.

Fluorescent multichannel sensor array based on three carbon dots derived from Tibetan medicine waste for the quantification and discrimination of multiple heavy metal ions in water.

A fluorescent multichannel sensor array has been established based on three carbon dots derived from Tibetan medicine waste for rapid quantification and discrimination of six heavy metal ions. Due to the chelation between metal ions and carbon dots (CDs), this fluorescence "turn off" mode sensing array can quantify six metal ions as low as "µM" level. Moreover, the six heavy metal ions display varying quenching effects on these three CDs owing to diverse chelating abilities between each other, producing differential fluorescent signals for three sensing channels, which can be plotted as specific fingerprints and converted into intuitive identification profiles via principal component analysis (PCA) and hierarchical cluster analysis (HCA) technologies to accurately distinguish Cu2+, Fe3+, Mn2+, Ag+, Ce4+, and Ni2+ with the minimum differentiated concentration of 5 µM. Valuably, this sensing array unveils good sensitivity, exceptional selectivity, ideal stability, and excellent anti-interference ability for both mixed standards and actual samples. Our contribution provides a novel approach for simultaneous determination of multiple heavy metal ions in environmental samples, and it will inspire the development of other advanced optical sensing array for simultaneous quantification and discrimination of multiple targets.

Construction of fluorescence and colorimetric tandem dual-mode sensor by modulating fluorescence and oxidase-like activity via valence switching of cerium-based coordination polymer nanoparticles for sarcosine detection.

A fluorescence and colorimetric tandem dual-mode sensor was established by modulating fluorescence and oxidase-like activity via valence switching of cerium-based coordination polymer nanoparticles (Ce-CPNs) for the detection of sarcosine (Sar) which is considered as a potential biomarker for the diagnosis of prostate cancer (PCa). In the present research, sarcosine oxidase (SOX) specifically catalyzes the oxidation of Sar to yield H2O2 which can rapidly oxidize Ce(III)-CPNs to generate Ce(IV)-CPNs in appropriate alkaline solution. The generated Ce(IV)-CPNs create a markedly weakened fluorescent signal at 350 nm, while they can induce oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to generate blue TMBox through emerging good oxidase-like activity. The sensing platform can realize accurate, stable, and high-throughput detection of Sar because of the tandem dual signal output mechanism. More attractively, the chromogenic hydrogel sensing device using smartphone photographing has achieved perfect results for the on-site sensing of Sar in urine specimens without large experimental equipments, demonstrating its considerable clinical application potential in the early diagnosis of PCa.

ZC3H4 regulates infiltrating monocytes, attenuating pulmonary fibrosis through IL-10.

Silicosis is a pulmonary fibrosis-associated disease caused by the inhalation of large amounts of free silicon dioxide (SiO2) that mainly manifests as early inflammation and late pulmonary fibrosis. As macrophage precursors, monocytes accumulate in the lung during early inflammation, but their role in the development of silicosis is unclear. Single-cell sequencing (cell numbers = 25,002), Western blotting, quantitative real-time PCR, ELISA and cell functional experiments were used to explore the specific effects of monocytes on fibroblasts. The CRISPR/Cas9 system was used to specifically knock down ZC3H4, a novel member of the CCCH zinc finger protein family, and was combined with pharmacological methods to explore the mechanism by which ZC3H4 affects chemokine and cytokine secretion. The results indicated that (1) SiO2 induced an infiltrating phenotype in monocytes; (2) infiltrating monocytes inhibited the activation, viability and migration of fibroblasts by regulating IL-10 but not IL-8; and (3) SiO2 downregulated IL-10 via ZC3H4-induced autophagy. This study revealed that ZC3H4 regulated the secretion function of monocytes, which, in turn, inhibited fibroblast function in early inflammation through autophagy signaling, thereby reducing pulmonary fibrosis. These findings provide a new idea for the clinical treatment of silicosis.

Dual-Targeting Nanoprobe for Early Diagnosis of Pheochromocytoma Though Coinstantaneous Identification of Circulating Tumor Cells.

Circulating tumor cells (CTCs) play a pivotal role in the early diagnosis of pheochromocytoma (PCC). Herein, we fabricated a new dual-targeting nanoprobe for coinstantaneous identification of rare PCC-CTCs from peripheral blood via targeting the norepinephrine transporter (NET) and somatostatin receptor SSTR2 overexpressed on the surface of PCC cells. Meta-iodobenzylguanidine (MIBG) functionalized magnetic Fe3O4 and octreotide (DOTA) decorated signal amplification Ag@SiO2 nanosphere were used to capture and detect PCC-CTCs by binding to NET and SSTR2. The proposed dual-targeting sensor achieved good reproducibility and high sensitivity for the monitoring of PC12 in the concentration range from 5 to 5 × 104 cells mL-1, with detection limits of 2 cell/mL. This strategy opens a new approach for simple, sensitive, and rapid determination of PCC biomarkers, which shows great potential in early diagnosis, prognosis, and therapeutic evaluation of PCC.

Fluorescence "Off-On" Probe for L-Cysteine Detection Based on Nitrogen Doped Carbon Dots.

Herein, a simple and efficient fluorescence analysis method for L-Cysteine (L-Cys) was established. The method was based on the fluorescent "off-on" mode of nitrogen doped carbon dots (NCDs). The NCDs were prepared via a facile one-step solvothermal method. In the process of exploring the bio-functional application of these newly synthesized NCDs, we found these NCDs with rich functional groups exhibited excellent optical properties. In addition, these newly synthesized NCDs showed an excitation-dependent emissions photolumine-scent (PL) property and exhibited good performance in the detection of Fe3+ ions by quenching the blue emission fluorescence. Interestingly, the quenched fluorescence of NCDs was recovered with the addition of L-Cys, which provided a novel approach for L-Cys detection. The NCDs-based fluorescent "off-on" sensor has a wide linear detection range (0-100 µM), and a relatively low detection limits (0.35 µM) for L-Cys. This simple fluorescent "off-on" approach is, very sensitive and selective for L-Cys detection, which also provides a new insight on NCDs biosensor application.

Size-Dependent Effect of Cu2O Nanocubes in Electrochemical and Photocatalytic Properties.

Cu2O nanocubes with different size (ranging from 20 nm to 400 nm) were prepared by a seed-mediated method to systematically explore the strong size-dependent properties in photocatalytic degradation of methyl orange (MO). Cu2O nanotubes were characterized by TEM, XRD, UV-Vis measurements. The size-dependent photocatalytic efficiency of the Cu2O nanocubes was evaluated by degradation of methyl orange (MO) in water under visible light (λ > 420 nm) irradiation. Furthermore, the photocurrent, linear sweep voltammetry (LSV) and electrochemical impedance spectra (EIS) measurements were applied to elucidate the size-dependent properties of Cu2O nanocubes, which demonstrated that smaller Cu2O nanocubes with certain length (30 nm) showed higher current density, faster electron transfer and lower rate of charge recombination in their exposed (100) facet. Therefore, 30 nm Cu2O nanocubes showed stronger visible light absorption capacity and higher photocatalytic activity in MO degradation among a series of nanocubes (20, 30, 100, 130, 200 and 400 nm) and their corresponding photocatalytic activities decreased with increasing the particles sizes.

Carbon dot-based fluorescent probe for early diagnosis of pheochromocytoma through identification of circulating tumor cells.

Pheochromocytoma (PCC), as a rare neuroendocrine tumor, is often missed or misdiagnosed because of its atypical clinical manifestations. To realize the early accurate diagnosis of PCC, we have selected circulating tumor cells (CTCs) with more complete biological information as biomarkers and developed a simple and novel fluorescence cytosensor. Octreotide-2,2',2'',2'''- (1,4,7,10 -tetraazacyclododecane-1,4,7,10-tetrayl) tetraacetic acid (DOTA) modified magnetic Fe3O4 and signal amplification CDs@SiO2 nanospheres are prepared to capture and detect PCC-CTCs from peripheral blood via binding to the somatostatin receptor SSTR2 overexpressed on the surface of PCC cells. During the detection process, the target cells were separated and enriched by magnetic capture probes (Fe3O4-DOTA), and then signal probes (CDs@SiO2-DOTA) could also specifically bound to target cells to form the sandwich-like structure for fluorescence signal output. The proposed fluorescence cytosensor has revealed good sensitivity and selectivity for quantitative analysis of PCC-CTCs in the concentration of 5-1000 cells mL-1 with a LOD of 2 cells mL-1. More importantly, designed fluorescence cytosensor has shown good reliability and stability in complex serum samples. This strategy provides a new way for detection of PCC-CTCs.

Molecular dynamics simulations of choline chloride and ascorbic acid deep eutectic solvents: Investigation of structural and dynamics properties.

Deep eutectic solvents (DESs) composed of choline chloride (ChCl) and ascorbic acid (AA) were investigated using the molecular dynamics (MD) simulations. The analyses of the configuration, radial distribution function (RDFs), coordination number, spatial distribution function (SDFs), interaction energies, hydrogen bond number, and self-diffusion coefficient of the ChCl/AA binary systems of different concentrations showed that the stability of the hydrogen bond network and the mutual attraction between systems were the strongest at the experimental eutectic concentration (molar ratio of 2:1). In our simulated temperature range from 303.15 to 353.15 K, the hydrogen bonding network of ChCl/AA DES does not undergo considerable alterations, indicating that its stability was insensitive to temperature. In addition, the influence of the water content on the ChCl/AA DES system was further investigated. The simulated results revealed that the water molecules could disrupt the formation of the hydrogen bonding network by occupyin positions that are essential for the formation of hydrogen bonds within the DES system.

Cascaded nanozyme-based high-throughput microfluidic device integrating with glucometer and smartphone for point-of-care pheochromocytoma diagnosis.

The development of point-of-care (POC) diagnostics devices for circulating tumor cells (CTCs) detection plays an important role in the early diagnosis of pheochromocytoma (PCC), especially in a low-resource setting. To further realize the rapid, portable, and high-throughput detection of CTCs, an Au@CuMOF cascade enzyme-based microfluidic device for instant point-of-care detection of CTCs was constructed by combining a smartphone application and a commercial portable glucose meter (PGM). In this microfluidic system, DOTA and norepinephrine (NE) modified Au@CuMOF signal probes and Fe3O4@SiO2 capture probes were used for the dual recognition and capture of rare PCC-CTCs. Then, the targeted binding of the Au@CuMOF cascade nanozymes to the CTCs endowed the cellular complexes with multienzyme mimetic activities (i.e., glucose oxidase-like and peroxidase-like activity) to catalyze glucose reduction as signal output for colorimetric and personal glucose meter (PGM) dual-mode detection of CTCs. The developed method has a linear range of 4 to 105 cells mL-1 and a detection limit of 3 cells mL-1. This method allows the simultaneous detection of six samples and demonstrates good applicability for CTCs detection in whole blood samples. More importantly, the combination of PGM, smartphone app and array microfluidic chips enables the rapid, portable, and high-throughput diagnoses of PCC, and providing provide a convenient and reliable alternative to traditional liquid biopsy diagnosis of various cancers.

A nanozyme multifunctional platform based on iron doped carbon dots derived from Tibetan Ganoderma lucidum waste for glucose sensing, anti-counterfeiting applications, and anticancer cell effect.

Implementing the concept of turning waste into treasure, the conversion of biomass waste into high-value carbon materials, especially carbon dots (CDs), has pointed out a new direction for disease diagnosis, tumor treatment, and other aspects. In this work, we have reported the GL-CDs(Fe) via a simple synthesis route exploiting Ganoderma lucidum waste as the precursor. Thanks to their excellent optical property and peroxidase mimetic activity, a novel GL-CDs(Fe)-based ratio fluorescence/colorimetric/smartphone triple mode sensing platform is cleverly fabricated for glucose determination with the LOD of 0.28, 0.37, and 0.52 µΜ separately. Especially, this triple mode biosensor is successfully utilized for glucose detection in serum samples with the relative error of less than ±8 % compared with clinical reports. Surprisingly, the GL-CDs(Fe) also presents immense application prospects in high-level anti-counterfeiting aspects due to their excellent luminescent properties, high water-solubility, and easy availability. Furthermore, GL-CDs(Fe) can catalyze excessive H2O2 inside tumor cells to produce massive hydroxyl radicals (·OH) which break down the redox levels of cancer cells and thereby eliminate tumor cells. Thus, this integrated "Three-in-One" multifunctional platform based on GL-CDs(Fe) unveils enormous research and application prospects for bio-sensing, anti-counterfeiting, cancer treatment.

Design and synthesis of novel 3-amino-5-phenylpyrazole derivatives as tubulin polymerization inhibitors targeting the colchicine-binding site.

As the basic unit of microtubules, tubulin is one of the most important targets in the study of anticarcinogens. A novel series of 3-amino-5-phenylpyrazole derivatives were designed and synthesized, and evaluates for their biological activities. Among them, a majority of compounds exerted excellent inhibitory activities against five cancer cell lines in vitro. Especially, compound 5b showed a strong antiproliferative activity against MCF-7 cells, with IC50 value of 38.37 nM. Further research indicated that compound 5b can inhibit the polymerization of tubulin targeting the tubulin colchicine-binding sites. Furthermore, 5b could arrest MCF-7 cells at the G2/M phase and induce MCF-7 cells apoptotic in a dose-dependent and time-dependent manners, and regulate the level of related proteins expression. Besides, compound 5b could inhibit the cancer cell migration and angiogenesis. In addition, 5b could inhibit tumor growth in MCF-7 xenograft model without obvious toxicity. All these results indicating that 5b could be a promising antitumor agent targeting tubulin colchicine-binding site and it was worth further study.

Design, synthesis, and biological evaluation of harmine derivatives as topoisomerase I inhibitors for cancer treatment.

A series of ß-carboline derivatives were designed and synthesized by introducing the chalcone moiety into the harmine. The synthesized derivatives were evaluated their anti-proliferative activities against six human cancer cell lines (MCF-7, MDA-MB-231, HepG2, HT29, A549, and PC-3) and one normal cell line (L02). Among them, compound G11 exhibited the potent anti-proliferative activity against MCF-7 cell line, with an IC50 value of 0.34 µM. Further biological studies revealed that compound G11 inhibited colony formation of MCF-7 cells, suppressed MCF-7 cell migration by downregulating migration-associated protein MMP-2. In addition, it could induce apoptosis of MCF-7 cells by downregulating Bcl-2 and upregulating Cleaved-PARP, Bax, and phosphorylated Bim proteins. Furthermore, compound G11 can act as a Topo I inhibitor, affecting DNA synthesis and transcription, thereby inhibiting cancer cell proliferation. Moreover, compound G11 inhibited tumor growth in 4T1 syngeneic transplant mice with an inhibition rate of 43.19 % at a dose of 10 mg/kg, and 63.87 % at 20 mg/kg, without causing significant toxicity to the mice or their organs, achieving the goal of reduced toxicity and increased efficacy. All these results indicate of G11 has enormous potential as an anti-tumor agent and merits further investigation.

LIMA1 links the E3 ubiquitin ligase RNF40 to lipid metabolism.

LIMA1 is a LIM domain and Actin binding 1 protein that acts as a skeleton protein to promote cholesterol absorption, which makes it an ideal target for interfering with lipid metabolism. However, the detailed regulation of LIMA1 remains unclear. Here, we identified that ring finger protein 40 (RNF40), an E3 ubiquitin ligase previously known as an epigenetic modifier to increase H2B ubiquitination, mediated the ubiquitination of LIMA1 and thereby promoted its degradation in a proteasome-dependent manner. Fraction studies revealed that the 1-166aa fragment of LIMA1 was indispensable for the interaction with RNF40, and at least two domains of RNF40 might mediate the association of RNF40 with LIMA1. Notably, treatment with simvastatin dramatically decreased the levels of CHO and TG in control cells rather than cells with overexpressed LIMA1. Moreover, RNF40 significantly decreased lipid content, which could be reversed by LIMA1 overexpression. These findings suggest that E3 ubiquitin ligase RNF40 could directly target LIMA1 and promote its protein degradation in cytoplasm, leading to the suppression of lipid accumulation mediated by LIMA1. Collectively, this study unveils that RNF40 is a novel E3 ubiquitin ligase of LIMA1, which underpins its high therapeutic value to combat dysregulation of lipid metabolism.

A dual-mode ratiometric fluorescence and smartphone-assisted colorimetric sensing platform based on bifunctional Fe,Co-CQD for glucose analysis at physiological pH.

Diabetes is a common and fatal chronic metabolic disease characterized by hyperglycemia, and thus monitoring blood glucose level is essential for early screening and timely control of disease. Herein, we have prepared the bifunctional iron and cobalt co-doped carbon quantum dot (Fe,Co-CQD) with good optical properties and peroxidase-mimetic catalytic activity toward specific substrate o-phenylenediamine (OPD) under alkaline condition. Glucose oxidase (GOx) specifically catalyzes the oxidation of glucose into H2O2, and Fe,Co-CQD subsequently triggers a reaction between H2O2 and OPD to form yellow product DAP with a distinct UV absorption peak at 420 nm. Simultaneously, the generated DAP also appears a well-defined fluorescence signal at 555 nm, which can suppress the intrinsic fluorescence peak of Fe,Co-CQD (439 nm) owing to the inner filter effect (IFE). Based on this principle, a dual-mode ratiometric fluorescence and colorimetric sensing platform has been constructed for glucose analysis at physiological pH, which reveals the advantages of excellent accuracy, high throughput, simple operation, and low cost. More importantly, a smartphone-assisted colorimetric sensing system based on a portable visual detection kit and a 3D printing smartphone-based device has been constructed, which enables on-site detection of glucose in complex serum samples without laboratory instruments, indicating its potential practical application prospect.

Recent Research Progress of Surface-Enhanced Raman Scattering Dominated Analysis Strategies in Early Diagnosis of Diseases.

Timely and powerful diagnostic means can achieve better therapeutic effects, reduce disease torment, and improve survival rate. As a powerful non-invasive spectroscopy technology, surface-enhanced Raman scattering (SERS) have testified to be a great potential candidate for extensive early clinical disease diagnosis. In recent years, the introduction of SERS label, combined with other analysis modes or artificial intelligence, and the emergence of miniaturized devices have made SERS technology more advantageous in early diagnosis of diseases. This review focuses on the research progress of SERS dominated analytical strategies in the field of early disease diagnosis in the past five years. The main content includes the application of label-free SERS detection; the construction of label SERS methodologies for various disease markers; SERS dominated multimode early disease diagnosis strategies; integration of SERS and artificial intelligence; portable Raman equipment and SERS imaging; and opportunities and trends for SERS diagnostic technology in the future.

Dual-targeting surface-enhancement Raman scattering tags based on silver nanocubes for early diagnosis of pheochromocytoma.

Pheochromocytoma (PCC), a rare tumor, often develops distant metastases after diagnosis, delaying early intervention treatment. In order to overcome the limitations of traditional diagnostic methods, dual-targeting Surface-Enhancement Raman Scattering (SERS) cytosensor was developed to identify and detect PCC-CTCs from peripheral blood. Meta-iodobenzylguanidine (MIBG) and octreotide-2,2',2″,2'''- (1,4,7,10 -tetraazacyclododecane-1,4,7,10-tetrayl) tetraacetic acid (DOTA) functionalized magnetic Fe3O4 and Ag-DTNB were prepared as capture probe and signal probe for SERS signal export, respectively. Ag nanocubes (AgNCs) as Raman active substrate offer an enhanced electromagnetic field, which could effectively enhance the signal intensity of DTNB and potentially realize trace analyte detection. The obtained SERS fingerprint spectroscopy possessed the characteristic of high sensitivity and resolution in the concentration range from 3.0-3.0 × 106 cells mL-1, with a detection limit of 1 cell mL-1, which laterally compensated the deficiency of scarce CTCs in peripheral blood. This work provided new insight into PCC-CTCs accurate detection.

Construction of ratiometric fluorescence sensor and test strip with smartphone based on molecularly imprinted dual-emission quantum dots for the selective and sensitive detection of domoic acid.

Domoic acid (DA), a highly neurotoxic metabolite produced by phytoplankton, contaminates seafood products and threats humankind. Herein, we have proposed a molecular imprinting fluorescence sensor with internal standard ratiometric mode for sensing of DA in seafood and seawater. In this study, the silicon-coated blue luminous carbon dots (B-CDs@SiO2) and CdTe acted as reference probe (430 nm) and response probe (610 nm), respectively. Subsequently, the two probes were assembled and the molecularly imprinted polymer (MIP) was introduced as the recognition element to construct the core component of the sensor (B-CDs@SiO2/CdTe MIP). When DA exists, it can be specifically adsorbed by the amino-rich imprinted sites on surface of B-CDs@SiO2/CdTe MIP and further assembled into the hydrogen-bonds complex, which can lead to the decrease in the fluorescence signal of MIP at 610 nm owing to the electron transfer from CdTe to DA. However, the fluorescence signal of MIP at 430 nm is not affected because of the protection of silica layer. Based on this principle, the designed internal standard ratiometric fluorescence sensor reveals high sensitivity, excellent selectivity, and wide linear range of 0.03-1 µM with a detection limit of 18 nM. Further, the portable fluorescent test strip with smartphone has been designed for semi-quantitative sensing of DA, which has potential application prospects for field analysis.

Development of fluorescence sensor and test paper based on molecularly imprinted carbon quantum dots for spiked detection of domoic acid in shellfish and lake water.

Excessive levels of domoic acid (DA) in edible shellfish and water can seriously threaten human health and even cause death. Herein, we have developed a fluorescence sensor and test paper based on molecularly imprinted carbon quantum dots (B-CDs@MIPs) for DA analysis. In this research, the prepared carbon quantum dots (B-CDs) with good optical properties were used as the sensitive fluorescent signal probes, and the molecularly imprinted polymers (MIPs) instead of biological antibodies were employed as the specific recognition components because of their high stability and low cost. Due to the shielding effect of imprinted silicon layer and the influence of modified groups introduced in the MIPs preparation process, the fluorescence signal of B-CDs in MIPs is inhibited. Interestingly, the DA can cause the partial recovery of the fluorescence intensity of B-CDs@MIPs by passivating the modified groups on the surface of B-CDs in MIPs. According to this principle, the designed fluorescence sensor reveals outstanding stability, super anti-interference ability, and excellent sensitivity, with the detection limit down to 10 nM. The sensor has been successfully applied to the rapid and accurate spiked analysis of DA in edible shellfish and lake water, providing excellent recoveries. More importantly, the designed inexpensive and easy-to-operate fluorescent test paper can realize preliminary qualitative analysis of DA on site by naked eye, indicating its promising application potential in food and environmental analysis.