Alkaline phosphatase-regulated in situ formation of chromogenic probes for multicolor visual sensing of biomarkers.

Alkaline phosphatase (ALP), as an immunological label, is widely used in biochemical assays. Here, a simple yet effective strategy for ALP activity detection was proposed on the basis of in situ formation of Prussian blue nanoparticles and polychromatic superposition effect. Firstly, ascorbic acid, a product from ALP-catalyzed hydrolysis of 2-phospho-l-ascorbic acid (AAP), converted yellow ferricyanide into ferrocyanide. Then, the specific reaction between ferrocyanide and ferric ions (Fe3+) initiated the generation of Prussian blue nanoparticles in situ. Meanwhile, the residual AAP chelated with Fe3+, and a stable Fe3+-AAP complex was quickly formed. When Prussian blue nanoparticles mixed with brown Fe3+-AAP complex and yellow ferricyanide at different ratios, a distinct color variation was presented. Therefore, a sensitive multicolor assay of ALP activity with a detection limit of 1.0 U/L was realized by simply blending commercially available reagents. Furthermore, magnetic sandwich and competitive sensing platforms for multiple biomarkers detection were constructed by combining the ALP-regulated multicolor system with the well-developed aptasensor. The feasibility of the sensors was convincingly demonstrated by using thrombin and prostate specific antigen as model targets. In addition, the proposed multicolor strategy was employed for evaluating inhibition efficiency, and shows potential in visual screening of enzyme inhibitors. Such a facile, sensitive and low-cost sensing strategy provides a new perspective to develop universal platforms of point-of-care testing.

Colloidal photonic crystal array chip based on nanoparticle self-assembly on patterned hydrophobic surface for signal-enhanced fluorescent assay of adenosine.

A controllable approach for preparing a portable colloidal photonic crystal (CPC) array chip is presented. The approach was inspired by the confinement effect of nanoparticle self-assembly on patterned surface. Hydrophobic polydimethylsiloxane substrate with reproducible micro-region array was fabricated by soft-lithography. The substrate was employed as the patterned template for self-assembly of monodisperse polystyrene nanoparticles. The CPC units can be prepared in several minutes, and exhibit consistent reflection wavelength. By adjusting the size of polystyrene nanoparticles and the shape of micro-regions, CPC units with multiple structure, colors and geometries were obtained. The CPC array chip features fluorescence enhancement owing to the optical modulation capability of the periodic nanostructure of the self-assembled CPC. With the reflection wavelength (523 nm) of green CPC units overlapping the emission wavelength (520 nm, with excitation wavelength of 490 nm) of 6-carboxyfluorescein-labeled DNA probe, the fluorescence intensity increased more than 10-fold. For signal-amplified assay of adenosine, the concentration range of linear response was 5.0 × 10-5 mol L-1 to 1.0 × 10-3 mol L-1, and the limit of detection was 1.3 × 10-6 mol L-1. Because of the enhancement effect of photonic crystal, the fluorescence images were more readable from the CPC array chip, compared with those from the planar substrate. The chip has potential applications in multiplex determination with high-throughput via encoding strategy based on the tunable structure, color or geometric shape. Graphical abstractSchematic diagram of signal-enhanced fluorescent detection of adenosine based on the colloidal photonic crystal array chip (PDMS, polydimethylsiloxane; PS NPs, polystyrene nanoparticles; CPC, colloidal photonic crystal; GO, graphene oxide; FAM, 6-carboxyfluorescein).

Multiplexed detection of micro-RNAs based on microfluidic multi-color fluorescence droplets.

In this work, simple, rapid, and low-cost multiplexed detection of tumor-related micro-RNAs (miRNAs) was achieved based on multi-color fluorescence on a microfluidic droplet chip, which simplified the complexity of light path to a half. A four-T-junction structure was fabricated to form uniform nano-volume droplet arrays with customized contents. Multi-color quantum dots (QDs) used as the fluorescence labels were encapsulated into droplets to develop the multi-path fluorescence detection module. We designed an integrated multiplex fluorescence resonance energy transfer system assisted by multiple QDs (four colors) and one quencher to detect four tumor-related miRNAs (miRNA-20a, miRNA-21, miRNA-155, and miRNA-221). The qualitative analysis of miRNAs was realized by the color identification of QDs, while the quantitative detection of miRNAs was achieved based on the linear relationship between the quenching efficiency of QDs and the concentration of miRNAs. The practicability of the multiplex detection device was further confirmed by detecting four tumor-related miRNAs in real human serum samples. The detection limits of four miRNAs ranged from 35 to 39 pmol/L was achieved without any target amplification. And the linear range was from 0.1 nmol/L to 1 µmol/L using 10 nL detection volume (one droplet) under the detection speed of 320 droplets per minute. The multiple detection system for miRNAs is simple, fast, and low-cost and will be a powerful platform for clinical diagnostic analysis. Graphical abstract.

Di (2-ethylhexyl) phthalate (DEHP)-induced hepatotoxicity in quails (Coturnix japonica) via triggering nuclear xenobiotic receptors and modulating cytochrome P450 systems.

Di (2-ethylhexyl) phthalate (DEHP) is a widely distributed pollutant that is of great concern due to its negative health effects. However, whether DEHP exposure causes liver toxicity in birds remains unclear. To clarify the potential hepatotoxicity of DEHP, quails were exposed to 0, 250, 500 and 1000 mg/kg BW/day DEHP by gavage treatment for 45 days. The livers of DEHP-exposed quails showed histomorphological changes. DEHP exposure induced a significant increase in cytochrome P450 enzyme system (CYP450s) activity (including aniline-4-hydroxylase (AH), aminopyrine N-demethylase (APND), erythromycin N-demethylase (ERND) and NADPH-cytochrome C reductase (NCR)) and in the contents of total cytochrome P450 (CYP450) and cytochrome b5 (Cyt b5) in quail liver. DEHP exposure also influenced the expression of nuclear xenobiotic receptors (NXRs) and CYP450 isoforms in the liver. The results suggested that DEHP-induced hepatotoxicity in quail liver is associated with activation of the NXRs pathway responses and disruption of CYP450s homeostasis. This study will help to further elucidate DEHP exposure-induced liver toxicity in quails.

Chemical metabolomics for investigating the protective effectiveness of Acanthopanax senticosus Harms leaf against acute promyelocytic leukemia.

Recent advances in the study of high-throughput metabolomics combined with high-resolution mass spectrometry have accelerated our understanding of the efficacy, mechanisms, and application of natural products. In this study, we have used chemical metabolomics to investigate and discover small molecule metabolites for the potential mechanism of Acanthopanax senticosus Harms leaf (ASL) against acute promyelocytic leukemia (APL). Based on high-throughput metabolomics, the underlying biomarker was found by combining chromatography coupled with quadrupole time-of-flight mass spectrometry with multivariate data analysis. The protective effect of ASL was dissected using biochemical indicators, pathology sections, immunohistochemistry, and multivariate analysis. Furthermore, 13 potential biomarkers associated with the pathway of sugar metabolism, amino-acid metabolism, nucleotide metabolism, and the metabolism of arachidonic acid were identified from serum samples. This study would help to understand chemical metabolomics for investigating the anti-APL effectiveness of ASL.

Quality Difference Study of Six Varieties of Ganoderma lucidum with Different Origins.

The quality difference of six varieties Ganoderma lucidum with different origins was investigated in this study by comparing the contents of ganoderic acid A and B, polysaccharide, and triterpenoids. The contents of ganoderic acid A and B in G. lucidum were analyzed by ultra performance liquid chromatography (UPLC). There was higher content of ganoderic acid A in G. lucidum of Dabie Mountain and Longquan. The G. lucidum from Longquan has the highest content of ganoderic acid B. The content of polysaccharide was determined by Anthrone-sulfuric acid method. The highest of polysaccharide content is G. lucidum from Liaocheng. The content of triterpenoid in G. lucidum was quantified by ultraviolet spectrophotometer at 548.1 nm using Ursolic acid as standard. The G. lucidum from Dabie Mountain has the highest content of triterpenoids. In summary, the content of ganoderic acid A and B, polysaccharide, and triterpenoids in G. lucidum with different origins are remarkably different, which may be caused by the conditions of cultivation and geographic environment.