Anthropogenic effects on soils in the eastern Tibetan Plateau revealed by geochemical elemental characteristics.

The Tibetan Plateau (TP) constitutes a fragile and sensitive ecological environment, which is vulnerable to global climate change and human activities. To investigate the anthropogenic effects on the TP's environmental system is valuable for guiding human responses and adaptations to future environmental changes. In this study, we detailedly analyzed the geochemical elements of four representative soil sections developed on loess from Ganzi, Jinchuan, Aba, and Chuanzhusi in the eastern TP. The chemical elemental profiles distinctly indicated the presence of typical anthropogenic elements (Cu, Zn, Ni, Cr, Pb, Mn, and Fe), underscoring the substantial influence of human activities on TP soil, and showing spatial variance. Our results indicate that anthropogenic impacts were relatively low at Aba and Ganzi, resulting in a deficit of anthropogenic elements at the surface layer. Whereas at Jinchuan and Chuanzhusi, relatively intense anthropogenic impacts have led to the enrichment of anthropogenic elements in the topsoil. We infer that agricultural activities, increased traffic, and expansion of tourism activities were the major factors affecting the anthropogenic elements of TP soils. Our study highlights the impact of human activities on soil geochemical processes in the Tibetan Plateau.

Characterisation of a SapYZU11@ZnFe2O4 biosensor reveals its mechanism for the rapid and sensitive colourimetric detection of viable Staphylococcus aureus in food matrices.

Although bacteriophage-based biosensors hold promise for detecting Staphylococcus aureus in food products in a timely, simple, and sensitive manner, the associated targeting mechanism of the biosensors remains unclear. Herein, a colourimetric biosensor SapYZU11@ZnFe2O4, based on a broad-spectrum S. aureus lytic phage SapYZU11 and a ZnFe2O4 nanozyme, was constructed, and its capacity to detect viable S. aureus in food was evaluated. Characterisation of SapYZU11@ZnFe2O4 revealed its effective immobilisation, outstanding biological activity, and peroxidase-like capability. The peroxidase activity of SapYZU11@ZnFe2O4 significantly decreased after the addition of S. aureus, potentially due to blockage of the nanozyme active sites. Moreover, SapYZU11@ZnFe2O4 can detect S. aureus from various sources and S. aureus isolates that phage SapYZU11 could not lyse. This may be facilitated by the adsorption of the special receptor-binding proteins on the phage tail fibre and wall teichoic acid receptors of S. aureus. Besides, SapYZU11@ZnFe2O4 exhibited remarkable sensitivity and specificity when employing colourimetric techniques to rapidly determine viable S. aureus counts in food samples, with a detection limit of 0.87 × 102 CFU/mL. Thus, SapYZU11@ZnFe2O4 has broad application prospects for the detection of viable S. aureus cells on food substrates.

Colorimetric detection of Staphylococcus aureus with enhanced sensitivity based on phage covalently immobilized Co3O4 nanozyme through synergistic inhibition effect.

Staphylococcus aureus (S. aureus) is a common foodborne pathogen, posing a serious threat to public health. Consequently, it is crucial to establish a platform for sensitive and specific determination of S. aureus in food. Herein, phage SapYZUH5, isolated by our lab, was covalently immobilized on Co3O4 to synthesize SapYZUH5@Co3O4. Notably, SapYZUH5@Co3O4 exhibited remarkable oxidase-like activity, enabling the catalysis of dissolved oxygen to generate superoxide anion free radicals and accelerate the TMB chromogenic reaction. Upon introduction of S. aureus, specific capture by SapYZUH5@Co3O4 resulted in inhibiting its oxidase-like activity and decelerating the 3,3',5,5'-tetramethylbenzidine (TMB) chromogenic reaction. Moreover, S. aureus can be lysed to release the reductive bacterial contents, which can further inhibit the TMB chromogenic reaction. Based on this principle, SapYZUH5@Co3O4 + TMB reaction system was employed for detection with enhanced sensitivity of S. aureus, yielding an equation: A = - 0.092 Log (CSA) + 0.79 (R2 = 0.987), with an ultralow limit of detection (LOD) of 28 CFU mL-1. This system exhibited remarkable specificity and anti-interfere towards S. aureus, owing to the excellent affinity of SapYZUH5 towards S. aureus. In addition, S. aureus in the actual food samples was detected using this system, yielding recoveries ranging from 96.34 to 109.43%, demonstrating its exceptional accuracy. Hence, our proposed covalent immobilization of phage on the nanozyme can realize sensitive and specific colorimetric determination of S. aureus in food samples.

Immobilization of a broad host range phage on the peroxidase-like Fe-MOF for colorimetric determination of multiple Salmonella enterica strains in food.

A broad host range phage-based nanozyme (Fe-MOF@SalmpYZU47) was prepared for colorimetric detection of multiple Salmonella enterica strains. The isolation of a broad host range phage (SalmpYZU47) capable of infecting multiple S. enterica strains was achieved. Then, it was directly immobilized onto the Fe-MOF to prepare Fe-MOF@SalmpYZU47, exhibiting peroxidase-like activity. The peroxidase-like activity can be specifically inhibited by multiple S. enterica strains, benefiting from the broad host range capture ability of Fe-MOF@SalmpYZU47. Based on it, a colorimetric detection approach was developed for S. enterica in the range from 1.0 × 102 to 1.0 × 108 CFU mL-1, achieving a low limit of detection (LOD) of 11 CFU mL-1. The Fe-MOF@SalmpYZU47 was utilized for detecting S. enterica in authentic food samples, achieving recoveries ranging from 91.88 to 105.34%. Hence, our proposed broad host range phage-based nanozyme exhibits significant potential for application in the colorimetric detection of pathogenic bacteria.

Enzyme-triggered in situ formation of Ag nanoparticles with oxidase-mimicking activity for amplified detection of alkaline phosphatase activity.

Given that alkaline phosphatase (ALP) is an important biomarker for many diseases, monitoring of its activity turns to be of great significance for related disease diagnosis and treatment. Herein, we report a new colorimetric assay based on the enzyme-triggered in situ formation of Ag nanoparticles (NPs) with high oxidase-mimicking activity for ALP activity detection. ALP first hydrolyzes the ascorbic acid phosphate (AAP) substrate to produce ascorbic acid (AA); the produced AA with strong reducing capacity then transforms Ag+ into Ag NPs; compared with the Ag+ precursor, the in situ formed Ag NPs have much higher oxidase-like activity to catalyze the 3,3',5,5'-tetramethylbenzidine (TMB) color reaction mediated by dissolved O2 at neutral pH. On the basis of this principle, amplified colorimetric detection of ALP activity with a linear scope of 0.15-5 U L-1 and a limit of detection down to 0.037 U L-1 was realized. In addition, our assay exhibited specific response toward ALP against other biological enzymes and species. Accurate and reliable determination of ALP activity in human plasma was also demonstrated by our assay, suggesting its great potential as a facile and efficient tool for monitoring of ALP activity in clinical practice.

Colorimetric determination of As(III) based on 3-mercaptopropionic acid assisted active site and interlayer channel dual-masking of Fe-Co-layered double hydroxides with oxidase-like activity.

A colorimetric method is described for the determination of As(III). It is based on the use of 3-mercaptopropionic acid (3-MPA) assisted active site and interlayer channel dual-masking of oxidase-like Fe-Co-layered double hydroxides (Fe-Co-LDH). The Fe-Co-LDH acts as an oxidase-mimicking nanozyme with high activity. It catalyzes the oxidation of colorless 3,3'5,5'-tetramethylbenzidine (TMB) to form a blue product (oxTMB) with an absorption maximum at 652 nm. It is found that As(III) firmly anchors onto the Fe* sites of the 3-MPA-modified Fe-Co-LDH via forming a stable Fe─As(III)─3-MPA─As(III)─Fe structure. This results in masking the active sites and interlayer channels of the Fe-Co-LDH nanozyme. As a result, the presence of As(III) as well as 3-MPA specifically inhibit the LDH-catalyzed chromogenic reaction. Based on the above principle, a colorimetric assay was designed for the determination of As(III). It provided linear response in the 0.10~8.33 µM As(III) concentration range and a detection limit as low as 35 nM. The assay was applied to the quantitation of As(III), even in the presence of potential interferents including As(V), Hg(II) and Pb(II), in environmental and drinking water samples. Graphical abstractSchematic illustration of the As(III) sensing mechanism based on 3-mercaptopropionic acid (3-MPA) assisted active site and interlayer channel dual-masking of Fe-Co-layered double hydroxides (Fe-Co-LDH) with oxidase-like activity. 3-MPA with sulfhydryl and carboxyl groups can assist As(III) to firmly anchor onto the Fe* sites inside the interlayer channels of the Fe-Co-LDH via forming a Fe─As(III)─3-MPA─As(III)─Fe structure, thus selectively resulting in a significant suppression of the chromogenic reaction.

Quantitative analysis of erythromycin, its major metabolite and clarithromycin in chicken tissues and eggs via QuEChERS extraction coupled with ultrahigh-performance liquid chromatography-tandem mass spectrometry.

A simple, rapid and novel method involving ultrahigh-performance liquid chromatography-electrospray ionization tandem triple quadrupole mass spectrometry (UHPLC-ESI-MS/MS) was developed to simultaneously detect erythromycin, its major metabolite and clarithromycin in chicken tissues (muscle, liver and kidney) and eggs (whole egg, albumen and yolk). Samples were extracted using acetonitrile-water (80:20, v/v), and a Cleanert MAS-Q cartridge was used to perform quick, easy, cheap, effective, rugged, and safe (QuEChERS) purification. The average recoveries were 87.78-104.22 %, and the corresponding intraday and interday relative standard deviations were less than 7.10 %. The decision limits and detection capabilities of the chicken tissues and eggs were 2.15-105.21 µg/kg and 2.26-110.42 µg/kg, respectively. For chicken tissues and eggs, the limits of detection and limits of quantification were 0.5 µg/kg and 2.0 µg/kg, respectively. The proposed method was successfully employed to analyse real samples, demonstrating its applicability.

Bimetallic AuNR@AgNCs for ultrasensitive surface-enhanced Raman scattering sensing of dithianon in apple juice.

In this study, a bimetallic surfaced-enhanced Raman spectroscopy (SERS)-active substrate consisting of AuNR@AgNCs was proposed for the rapid detection of dithianon. Due to the significant synergistic enhancement of the core-shell nanocuboids, the obtained AuNR@AgNC substrate exhibited excellent SERS performance. The simulation findings supported the practical SERS results and demonstrated that interactions were mainly maintained by the nitrile functional group. The AuNR@AgNCs could be used to detect dithianon with an LOD value of 20 nM. Moreover, dithianon in river water and apple juice could be detected with recovery in the satisfactory ranges of 97.41%-98.35% and 97.77%-98.70%, respectively, by using this substrate under optimal conditions, indicating that the AuNR@AgNC substrate could serve as an excellent SERS detection platform for pesticide residues in fruit.

Competitive immunoassay using enzyme-regulated Fe3O4@COF/Fe3+ fluorescence probe for natural chloramphenicol detection.

Accurate and sensitive detection of chloramphenicol (CAP) in natural samples is essential for ensuring human health. Herein, an enzyme-regulated fluorescence sensor using Fe3O4@COF/Fe3+ probe, is developed for CAP determination. Fe3O4@COF, synthesized via hydrothermal method, exhibits dual functions as a magnetic carrier and signal probe. Bovine serum albumin conjugated-chloramphenicol, adsorbed on the surface of Fe3O4@COF, competes with CAP for antibody binding. The antibody interacts with alkaline phosphatase via the biotin-streptavidin system. Meanwhile, ascorbic acid, produced from the enzyme-catalyzed reaction dominated by alkaline phosphatase, effectively restores the fluorescence of Fe3O4@COF that is quenched by Fe3+. After experimental verification and gradual optimization, a logarithmic linear relationship between CAP concentration and fluorescence intensity is established in the range of 2 × 10-4∼10 µg mL-1, with a good limit of detection (9.2 × 10-5 µg mL-1). Proposed method exhibits excellent stability (15 days) and reusability (8 cycles), providing a sensitive and reliable method for accurate CAP detection. The readouts show good agreement with HPLC and recoveries during laboratory and natural CAP analysis.

An advanced ratiometric molecularly imprinted sensor based on metal ion reoxidation for indirect and ultrasensitive glyphosate detection in fruit.

An indirect and ultrasensitive ratiometric molecularly imprinted (MIP) sensor, based on metal ion reoxidation, is introduced for glyphosate (GLY) determination in fruit. As high-performance signal amplification substrates, carbon nanotubes (MWCNTs) and gold nanoparticles (AuNPs) are conveniently modified on GCE. The artificial antibody-MIP membrane, presents typical three-dimensional structure to GLY template. Built-in reference methylene blue (MB) is directly electropolymerized on MWCNTs-Au/GCE. Particularly, Cu2+ and GLY interestingly form chelate complex, and the Cu2+ (ICu) in Cu(Ⅱ)-GLY-complex can be reoxidized, and indirectly quantizes GLY. The reference signal (IMB) presents noteworthy stability with different GLY levels, and the ratiometric readout (ICu/IMB) is recognized as a more trustworthy indicator to quantize GLY. Proposed sensor presents broad range as 1.73 âˆ¼ 400 ng/mL, and limit of detection is well found as 0.24 ng/mL (S/N = 3). Finally, as-fabricated method is verified with standard HPLC in real-fruit-sample, and the errors and recovery rates are calculated as 3.4% âˆ¼ 6.7% and 94.4% âˆ¼ 104.6%, respectively.

Versatile dodecyl trimethyl ammonium bromide modified γ-FeOOH for simultaneous removal and determination of As(⠤).

Inorganic arsenic pollution in water spreads all over the world, tremendously threatening environmental safety and human health. Herein, versatile dodecyl trimethyl ammonium bromide modified γ-FeOOH (DTAB-γ-FeOOH) was prepared for sportive removal and visual determination of As(Ⅴ) in water. DTAB-γ-FeOOH displays a nanosheet-like structure with a high specific surface area calculated as 166.88 m2 g-1. Additionally, DTAB-γ-FeOOH shows peroxidase-mimicking feature, which can catalyze colorless TMB to generate blue oxidized TMB (TMBox) in presence of H2O2. Removal experiments show that DTAB-γ-FeOOH exhibits good As(Ⅴ) removal efficiency because modification of DTAB makes γ-FeOOH carry abundant positive charges, improving affinity between DTAB-γ-FeOOH and As(Ⅴ). It is found that theoretical maximum adsorption capacity is up to 126.91 mg g-1. Moreover, DTAB-γ-FeOOH can resist interference of most of co-existing ions. After that, As(Ⅴ) was detected based on peroxidase-like DTAB-γ-FeOOH. As(Ⅴ) can be adsorbed onto DTAB-γ-FeOOH surface, markedly inhibiting its peroxidase-like activity. Based on it, As(Ⅴ) ranging from 1.67 to 3333.33 µg L-1 can be well detected, with a low LOD (0.84 µg L-1). The successful sorptive removal and visual determination of As(Ⅴ) from real environmental water indicated that DTAB-γ-FeOOH has great potential in the treatment of As(Ⅴ)-containing environment water.

Surface engineering of magnetic peroxidase mimic using bacteriophage for high-sensitivity/specificity colorimetric determination of Staphylococcus aureus in food.

Herein, we proposed surface engineering of magnetic peroxidase mimic using bacteriophage by electrostatic interaction to prepare bacteriophage SapYZU15 modified Fe3O4 (SapYZU15@Fe3O4) for colorimetric determination of S. aureus in food. SapYZU15@Fe3O4 exhibits peroxidase-like activity, catalyzing 3,3',5,5'-tetramethylbenzidine (TMB) chromogenic reaction. After introducing S. aureus, peroxidase-like activity of SapYZU15@Fe3O4 was specifically inhibited, resulting in deceleration of TMB chromogenic reaction. This phenomenon benefits from the presence of unique tail protein gene in the bacteriophage SapYZU15 genome, leading to a specific biological interaction between S. aureus and SapYZU15. On basis of this principle, SapYZU15@Fe3O4 can be employed for colorimetric determination of S. aureus with a limiting detection (LOD), calculated as low as 1.2 × 102 CFU mL-1. With this proposed method, colorimetric detection of S. aureus in food was successfully achieved. This portends that surface engineering of nanozymes using bacteriophage has great potential in the field of colorimetric detection of pathogenic bacterium in food.

Whole-genome analysis showed the promotion of genetic diversity and coevolution in Staphylococcus aureus lytic bacteriophages and their hosts mediated by prophages via worldwide recombination events.

Prophages as a part of Staphylococcus aureus genome contribute to the genetic diversity as well as survival strategies of their host. Some S. aureus prophages also have an imminent risk of host cell lysis and become a lytic phage. Nonetheless, interactions among S. aureus prophages, lytic phages, and their hosts, as well as the genetic diversity of S. aureus prophages, remain unclear. We identified 579 intact and 1,389 incomplete prophages in the genomes of 493 S. aureus isolates obtained from the NCBI database. The structural diversity and gene content of intact and incomplete prophages were investigated and compared with 188 lytic phages. Mosaic structure comparison, ortholog group clustering, phylogenetic analysis, and recombination network analysis were performed to estimate genetic relatedness among S. aureus intact prophages, incomplete prophages, and lytic phages. The intact and incomplete prophages harbored 148 and 522 distinct mosaic structures, respectively. The major difference between lytic phages and prophages was the lack of functional modules and genes. Compared to the lytic phages, both the S. aureus intact and incomplete prophages harbored multiple antimicrobial resistance (AMR) and virulence factor (VF) genes. Several functional modules of lytic phages 3_AJ_2017 and 23MRA shared more than 99% nucleotide sequence identity with S. aureus intact (ST20130943_p1 and UTSW_ MRSA_55_ip3) and incomplete prophages (SA3_LAU_ip3 and MRSA_FKTN_ip4); other modules showed little nucleotide sequence similarity. Ortholog and phylogenetic analyses revealed a common gene pool shared between the prophages and lytic Siphoviridae phages. Moreover, most shared sequences existed within intact (43428/137294, 31.6%) and incomplete prophages (41248/137294, 30.0%). Therefore, the maintenance or loss of functional modules in intact and incomplete prophages is key to balance the costs and benefits of large prophages harboring various AMR and VF genes in the bacterial host. The shared identical functional modules between S. aureus lytic phages and prophages are likely to result in the exchange, acquisition, and loss of functional modules, and therefore contribute to their genetic diversity. Moreover, constant recombination events within prophages globally were responsible for the coevolution of lytic phages and their bacterial hosts.

A smartphone-integrated colorimetric quantitative analysis platform based on oxidase-like Ce(IV)-ATP-Tris CPNs/CNF test strip for detection of inorganic arsenic in rice.

Herein, a colorimetric sensing system based on cerium(IV) coordination polymer nanoparticles (Ce(IV)-ATP-Tris CPNs) was proposed for As(V) detection. Ce(IV)-ATP-Tris CPNs show excellent oxidase-like activity, triggering 3,3',5,5'-tetramethylbenzidine (TMB) chromogenic reaction. With addition of ascorbic acid 2-phosphate (AAP) and acid phosphatase (ACP), ACP can hydrolyze AAP to produce antioxidative ascorbic acid (AA), inhibiting TMB chromogenic reaction. After that, introduction of As(V) can inhibit ACP, recovering TMB chromogenic reaction. Therefore, sensitive and selective As(V) detection is achieved. Moreover, Ce(IV)-ATP-Tris CPNs were transformed into cellulose nanofiber (CNF) to form test strip (Ce(IV)-ATP-Tris CPNs/CNF). Inorganic arsenic in rice can be detected by test strip, color of that can be measured by smartphone-integrated colorimetric quantitative analysis platform. Given this, rapid and convenient strip test of inorganic arsenic in rice by using this platform was achieved. Hence, this platform possesses great application potential in the field of inorganic arsenic in rice, even food safety.

Thermal-controlled active sensor module using enzyme-regulated UiO-66-NH2/MnO2 fluorescence probe for total organophosphorus pesticide determination.

An enzyme-regulated UiO-66-NH2/MnO2 fluorescence sensor, fully functionalized with spectrometric capacities, is developed for budget-friendly total organophosphorus pesticides (OPs) determination. The fluorescence probe, UiO-66-NH2/MnO2, is hydrothermally synthesized and morphologically examined. A specialized enzyme-catalyzed reaction, which can be gradually inhibited by OPs, is designed with participations of alkaline phosphatase (ALP) and sodium L-ascorbyl-2-phosphate (AAP). The reaction product of ascorbic acid (AA) decomposes MnO2 and restores UiO-66-NH2 fluorescence, establishing a relationship between OPs level and fluorescence intensity. Interactions among UiO-66-NH2, MnO2, OPs, and AA are clarified. Stepwise optimizations are performed to the UiO-66-NH2/MnO2 probe, ensuring considerable advantages as OPs affinity and fluorescence quenching behavior over rival nanomaterials. Analytical advances are magnified by fabricating an active sensor module, with self-acting thermal regulation for optimal enzyme activity. Under 4 and 20 °C environment, regulation period is less than 40 and 100 s. In total OPs determination for laboratorial and real-vegetable samples, this method exhibits uniform and log-linear responses to common species of OPs in a range as 1.0 × 10-7~10 mg L-1, and limit of detection is established as 8.9 × 10-8 mg L-1. Proposed readouts are validated with certified HPLC and recovery test. Relative errors and recovery rates are found as 2.7-6.4% and 95.8-102.6%, respectively.

A single-nanozyme colorimetric array based on target-induced differential surface passivation for quantification and discrimination of Cl-, Br- and I- ions.

Abnormal levels of halide ions in drinking water have enormous threats to human health, and thus designing reliable and sensitive methods to quantify and distinguish these ions becomes extremely crucial. Herein, we develop a single-nanozyme colorimetric array based on target-induced differential surface passivation for the quantification and discrimination of Cl-, Br- and I- ions. Silver citrate (Ag3Cit) is designed as an oxidase mimic to efficiently catalyze the 3,3',5,5'-tetramethylbenzidine (TMB) chromogenic reaction. When halide ions (Cl-, Br- and I-) are present, due to their different precipitation interactions with the Ag(Ⅰ) entity in Ag3Cit, they can passivate the active surface of the nanozyme to various degrees, resulting in the inhibited TMB chromogenic reaction differentially. According to this principle, simple and efficient quantitative detection of Cl-, Br- and I- ions was achieved, with all the detection limits down to the nM level. By employing Ag3Cit as a single sensing element, a nanozyme catalysis-based colorimetric array was further established, and both individual and mixed ions were successfully distinguished by integrating the array with principal component analysis. Accurate identification of unknown samples was also verified via a double-blind protocol, indicating potential applications of the array in practice.

Programmable-Printing Paper-Based Device with a MoS2 NP and Gmp/Eu-Cit Fluorescence Couple for Ratiometric Tetracycline Analysis in Various Natural Samples.

Paper-based fluorescence devices, with smartphone aids, bring considerable operation convenience for tetracycline (TC) sensing. Nevertheless, they must meet the challenge in real determination against complicated backgrounds. Considering that, we present a programmable-printing paper-based device and then apply it to TC determination for various natural samples. MoS2 NPs and Gmp/Eu-Cit are synthetized as composite probes. A static quenching process is found with MoS2 NP fluorescence at 430 nm, while significant magnification of Gmp/Eu-Cit emission is obtained at 617 nm, establishing a valuable ratiometric indicator. Remarkably, two-stage programmable printing maximizes the proposed sensing capability. A transitive device, containing a gradually changing amount of a certain probe, is prepared to sense TC. With a homemade smartphone application and 3D-printed measurement chamber, the corresponding signals are examined to explore optimal setups. These setups are automatically processed to prepare the final-version device, not requiring manual operations. Benefitting from this interesting feature, the proposed device gains many rewards in performances. It effectively senses TC in a wide range from 12.7 nM to 80 µM and simultaneously provides naked eye-legible signals and smartphone-based readouts with confident selectivity and stability. This device is consequently applied for various samples of soil, river water, milk, and serum and meets well with HPLC-MS and recovery tests.

MicroRNA-603 Promotes Progression of Cutaneous Melanoma by Regulating TBX5.

BACKGROUND: Although studies manifested that microRNA-603 plays a vital role in many cancers, the modulatory mechanism of microRNA-603 in cutaneous melanoma remains unknown. We aimed to investigate the roles of microRNA-603 in cutaneous melanoma cells. METHODS: First, microRNA-603 expression in cutaneous melanoma cell lines was detected by qRT-PCR. The mRNA and protein expression levels of TBX5 in cutaneous melanoma cell lines were tested by qRT-PCR and western blot, respectively. In addition, the interaction between microRNA-603 and TBX5 was determined by dual-luciferase reporter gene assay, and their impacts on the growth of cutaneous melanoma cells were detected by cellular function experiments such as MTT, colony formation, and Transwell assays. RESULTS: The expression level of microRNA-603 in human cutaneous melanoma cells was relatively upregulated. Overexpressing microRNA-603 could promote progression of cutaneous melanoma cells, while silencing microRNA-603 expression could suppress the malignant progression of cutaneous melanoma. In addition, TBX5 was lowly expressed in cutaneous melanoma cells. As confirmed by dual-luciferase assay, microRNA-603 could specifically bind to 3'UTR of TBX5 and regulate TBX5. The results of the rescue experiment demonstrated that inhibiting microRNA-603 expression could suppress the proliferation, migration, and invasion of cutaneous melanoma cells, but its suppressive effect could be restored by TBX5. CONCLUSION: MicroRNA-603 could regulate the expression of TBX5, thus promoting the malignant progression of cutaneous melanoma cells.

One-pot construction of acid phosphatase and hemin loaded multifunctional metal-organic framework nanosheets for ratiometric fluorescent arsenate sensing.

Exploring high-performance sensors for toxic arsenic detection is highly desired because of its great threat to the environment. Herein, we report a ratiometric fluorescent biosensor based on acid phosphatase and hemin loaded multifunctional Zn-based metal-organic framework (ACP/hemin@Zn-MOF) for high-performance arsenate (As(Ⅴ)) sensing. ACP/hemin@Zn-MOF is constructed by self-assembly, where hemin exhibits peroxidase-like activity and 2-aminoterephthalic acid ligand endows ACP/hemin@Zn-MOF with an intrinsic fluorescence (452 nm). When ACP/hemin@Zn-MOF catalyzes the oxidation of o-phenylenediamine (OPD), fluorescent 2,3-diaminophenazine (DAP) with an emission signal (564 nm) is produced and weakens ACP/hemin@Zn-MOF intrinsic fluorescence (452 nm) due to inner filter effect; after adding ascorbic acid 2-phosphate (AAP), ACP can hydrolyze AAP and produce ascorbic acid, which competitively suppresses the oxidation of OPD, resulting in the decrease of DAP signal (564 nm) and the recovery of ACP/hemin@Zn-MOF signal (452 nm); when As(V) is added, it irreversibly poisons ACP against hydrolyzing AAP, and the fluorescence signal at 564 nm recovers and the one at 452 nm is suppressed again. High-sensitivity and high-selectivity detection of As(V) (3.33-300 µg L-1) is realized, with a detection limit of 1.05 µg L-1. The biosensor was also successfully employed to detect total arsenic and As(V) in rice.

A portable test strip based on fluorescent europium-based metal-organic framework for rapid and visual detection of tetracycline in food samples.

Residual tetracycline (TC) in animal food caused by abuse of antibiotics leads to many chronic diseases in the human body. The development of a simple and on-site visualization method for TC detection is need of the hour. Herein, a fluorescent europium-based metal-organic framework (Eu-MOF) sensor for visual and rapid detection of TC was developed. Eu-MOF displays a red emission being excited at 260 nm. Upon exposure to TC, significant fluorescence quenching was observed due to the inner filter effect and photoinduced electron transfer. Moreover, the developed sensor was applied for the detection of TC in milk and beef samples with recoveries of 96.1% to 106.3%, respectively. More importantly, a portable test strip based on Eu-MOF was manufactured. It is a highly selective and sensitive portable device for TC detection. The results can be distinguished immediately by naked eyes, making it become an excellent choice to detect TC in real-time application.