Label-Free and Enzyme-Free Homogeneous Electrochemical Biosensing Strategy Based on Hybridization Chain Reaction: A Facile, Sensitive, and Highly Specific MicroRNA Assay

Homogenous electrochemical biosensing strategies have attracted substantial attention, because of their advantages of being immobilization-free and having rapid response and improved recognition efficiency, compared to heterogeneous biosensors; however, the high cost of labeling and the strict reaction conditions of tool enzymes associated with current homogeneous electrochemical methods limit their potential applications. To address these issues, herein we reported, for the first time, a simple label-free and enzyme-free homogeneous electrochemical strategy based on hybridization chain reaction (HCR) for sensitive and highly specific detection of microRNA (miRNA). The target miRNA triggers the HCR of two species of metastable DNA hairpin probes, resulting in the formation of multiple G-quadruplex-incorporated long duplex DNA chains. Thus, with the electrochemical indicator Methylene Blue (MB) selectively intercalated into the duplex DNA chain and the multiple G-quadruplexes, a significant electrochemical signal drop is observed, which is dependent on the concentration of the target miRNA. Thus, using this “signal-off” mode, a simple, label-free and enzyme-free homogeneous electrochemical strategy for sensitive miRNA assay is readily realized. This strategy also exhibits excellent selectivity to distinguish even single-base mismatched miRNA. Furthermore, this method also exhibits additional advantages of simplicity and low cost, since both expensive labeling and sophisticated probe immobilization processes are avoided. Therefore, the as-proposed label-free and enzyme-free homogeneous electrochemical strategy may become an alternative method for simple, sensitive, and selective miRNA detection, and it has great potential to be applied in miRNA-related clinical diagnostics and biochemical research

Engineering Natural Materials as Surface-Enhanced Raman Spectroscopy Substrates for In situ Molecular Sensing

Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical tool. However, its applications for in situ detection of target molecules presented on diverse material surfaces have been hindered by difficulties in rapid fabricating SERS-active substrates on the surfaces of these materials through a simple, low-cost, and portable approach. Here, we demonstrate our attempt to address this issue by developing a facile and versatile method capable of in situ generating silver nanoparticle film (SNF) on the surfaces of both artificial and natural materials in a simple, cheap, practical, and disposable manner. Taking advantage of the high SERS enhancement ability of the prepared SNF, the proposed strategy can be used for in situ inspecting herbicide and pesticide residues on vegetables, as well as the abuse of antiseptic in aquaculture industry. Therefore, it opens new avenues for advancing the application prospects of SERS technique in the fields of food safety, drug security, as well as environment monitoring

Table_1_Growth of tomato and cucumber seedlings under different light environments and their development after transplanting.docx

Selecting suitable light conditions according to the plant growth characteristics is one of the important approaches to cultivating high-quality vegetable seedlings. To determine the more favorable LED light conditions for producing high-quality tomato and cucumber seedlings in plant factories with artificial light (PFALS), the growth characteristics of tomato and cucumber seedlings under seven LED light environments (CK, B, UV-A, FR, B+UV-A, UV-A+FR, and B+FR) and the development of these seedlings after transplanting into a plastic greenhouse were investigated. The results showed that the seedling height and hypocotyl length increased in treatments with far-red light supplementation (FR, UV-A+FR, and B+FR), but decreased in the B treatment, in both varieties. The seedling index of tomato seedlings increased in the B+UV-A treatment, while that of cucumber seedlings increased in the FR treatment. After transplanting into a plastic greenhouse, tomato plants that radiated with UV-A had greater flower numbers on the 15th day after transplanting. In cucumber plants of the FR treatment, the flowering time was significantly delayed, and the female flower exhibited at a lower node position. By using a comprehensive scoring analysis of all detected indicators, light environments with UV-A and FR were more beneficial for improving the overall quality of tomato and cucumber seedlings, respectively.</p

Layered Double Hydroxide Functionalized Textile for Effective Oil/Water Separation and Selective Oil Adsorption

The removal of oil and organic pollutants from water is highly desired due to frequent oil spill accidents, as well as the increase of industrial oily wastewater. Here, superhydrophobic and superoleophilic textile has been successfully prepared for the application of effective oil/water separation and selective oil adsorption. This textile was fabricated by functionalizing the commercial textile with layered double hydroxide (LDH) microcrystals and low surface energy molecules. The LDH microcrystals were immobilized on the microfibers of the textile through an in situ growth method, and they formed a nestlike microstructure. The combination of the hierarchical structure and the low surface energy molecules made the textile superhydrophobic and superoleophilic. Further experiments demonstrated that the as-prepared textile not only can be applied as effective membrane materials for the separation of oil and water mixtures with high separation efficiency (>97%), but also can be used as a bag for the selective oil adsorption from water. Thus, such superhydrophobic and superoleophilic textile is a very promising material for the application of oil spill cleanup and industrial oily wastewater treatment

Layered Double Hydroxide Functionalized Textile for Effective Oil/Water Separation and Selective Oil Adsorption

The removal of oil and organic pollutants from water is highly desired due to frequent oil spill accidents, as well as the increase of industrial oily wastewater. Here, superhydrophobic and superoleophilic textile has been successfully prepared for the application of effective oil/water separation and selective oil adsorption. This textile was fabricated by functionalizing the commercial textile with layered double hydroxide (LDH) microcrystals and low surface energy molecules. The LDH microcrystals were immobilized on the microfibers of the textile through an in situ growth method, and they formed a nestlike microstructure. The combination of the hierarchical structure and the low surface energy molecules made the textile superhydrophobic and superoleophilic. Further experiments demonstrated that the as-prepared textile not only can be applied as effective membrane materials for the separation of oil and water mixtures with high separation efficiency (>97%), but also can be used as a bag for the selective oil adsorption from water. Thus, such superhydrophobic and superoleophilic textile is a very promising material for the application of oil spill cleanup and industrial oily wastewater treatment

Layered Double Hydroxide Functionalized Textile for Effective Oil/Water Separation and Selective Oil Adsorption

The removal of oil and organic pollutants from water is highly desired due to frequent oil spill accidents, as well as the increase of industrial oily wastewater. Here, superhydrophobic and superoleophilic textile has been successfully prepared for the application of effective oil/water separation and selective oil adsorption. This textile was fabricated by functionalizing the commercial textile with layered double hydroxide (LDH) microcrystals and low surface energy molecules. The LDH microcrystals were immobilized on the microfibers of the textile through an in situ growth method, and they formed a nestlike microstructure. The combination of the hierarchical structure and the low surface energy molecules made the textile superhydrophobic and superoleophilic. Further experiments demonstrated that the as-prepared textile not only can be applied as effective membrane materials for the separation of oil and water mixtures with high separation efficiency (>97%), but also can be used as a bag for the selective oil adsorption from water. Thus, such superhydrophobic and superoleophilic textile is a very promising material for the application of oil spill cleanup and industrial oily wastewater treatment

Amplified Detection of T4 Polynucleotide Kinase Activity by the Coupled λ Exonuclease Cleavage Reaction and Catalytic Assembly of Bimolecular Beacons

The phosphorylation of nucleic acid catalyzed by polynucleotide kinase is an indispensible procedure involved in many vital cellular activities such as DNA recombination and DNA repair. Herein, a novel strategy for the sensitive determination of T4 polynucleotide kinase (PNK) activity and inhibition was proposed, which combined exonuclease enzyme reaction and bimolecular beacons (bi-MBs)-based signal amplification. A hairpin probe (HP) with 5′-hydroxyl termini and two different types of molecular beacons (MBs), MB1 and MB2, is designed. Taking advantage of the efficient enzyme reactions, namely the phosphorylation of HP by PNK and the λ exonuclease cleavage reaction, the trigger DNA fragment can be released from HP and is used to trigger the catalytic assembly of bimolecular beacons, resulting in a remarkably amplified fluorescence signal toward PNK activity detection. The detection limit of this method toward PNK was obtained as 1 mU/mL, which was superior or comparable with the reported methods. Furthermore, the facile and sensitive method can also be used to screen the inhibition effects toward several common inhibitors. It provides a promising platform for sensitive determination of nucleotide kinase activity and inhibition, and also shows great potential for biological process research, drug discovery, and clinic diagnostics

Additional file 4 of Identification of key gene networks related to the freezing resistance of apricot kernel pistils by integrating hormone phenotypes and transcriptome profiles

Additional file 4: Table S5. The expression level of DEGs related to plant hormone signaling transduction in two apricot kernel cultivars under freezing stress

Additional file 5 of Identification of key gene networks related to the freezing resistance of apricot kernel pistils by integrating hormone phenotypes and transcriptome profiles

Additional file 5: Table S6. Annotation of hub genes in the brown module