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In recent years, the development of photovoltaic assisted electrocatalytic ( PV-EC) water splitting has emerged as a critical issue in achieving carbon neutrality through green hydrogen evolution. However, traditional electrocatalysts do not meet the high solar-to-hydrogen ( STH) conversion efficiency requirements for PV-EC systems. Therefore, it is crucial to obtain electrocatalysts with low cost and reaction overpotential. In this work, transition metal W with high valence states was employed to dope NiFe phosphide, and NiFeW ternary phosphides were prepared by a simple one-step electrodeposition method. The results indicate that NiFeW phosphide has excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities. Furthermore, when used as a bifunctional electrocatalyst, NiFeW phosphide shows a 51 mV reduction in overpotential at a current density of 10 mA/cm2 compared to NiFe phosphide sample. Finally, NiFeW phosphide and a-Si:H/a-SiGe:H/a-SiGe:H solar cell are employed as bifunctional electrocatalyst and driving source, respectively. The PV-EC devices achieve above 7% theoretical STH efficiency, which is significant for practical applications of solar to hydrogen devices. [ABSTRACT FROM AUTHOR]

This study aims to establish a time-resolved fluorescence immunochromatography method for simultaneous determination of human papillomavirus (HPV) type 16 E6 and L1 protein concentrations. The amount of lanthanide microsphere-labeled antibodies, the concentration of coated antibodies, and the reaction time were optimized, and then a test strip for the simultaneous determination of the protein concentrations was prepared. The performance of the detection method was evaluated based on the concordance of the results from clinical practice. The optimal conditions were 8 μg and 10 μg of HPV16 L1 and E6-labeled antibodies, respectively, 1.5 mg/mL coated antibodies, and reaction for 10 min. The detection with the established method for L1 and E6 proteins showed the linear ranges of 5-320 ng/mL and 2-64 ng/mL and the lowest limits of detection of 1.78 ng/mL and 1.09 ng/mL, respectively. There was no cross reaction with human immunodeficiency virus (HIV), treponema pallidum (TP), or HPV18 E6 and L1 proteins. The average recovery rate of the established method was between 97% and 107%. The test strip prepared in this study showed the sensitivity, specificity, and diagnostic accuracy of 97.46%, 90.57%, and 95.32%, respectively, in distinguishing patients with cervical cancer and precancerous lesions from healthy subjects, with the area under the curve (AUC) of 0.980 1 and 95% Confidence Interval (CI) of 0.956 5 to 1.000 0. The time-resolved fluorescence immunochromatography combined with the test strips prepared in this study showed high sensitivity, high accuracy, simple operation, and rapid reaction in the quantitation of HPV16 E6 and L1 proteins. It thus can be used as an auxiliary method for the diagnosis and early screening of cervical cancer and precancerous lesions and the assessment of disease course.

A fusion protein containing a tetanus toxin peptide, a tuftsin peptide and a SARS-CoV-2S protein receptor-binding domain (RBD) was prepared to investigate the effect of intramolecular adjuvant on humoral and cellular immunity of RBD protein. The tetanus toxin peptide, tuftsin peptide and S protein RBD region were connected by a flexible polypeptide, and a recombinant vector was constructed after codon optimization. The recombinant S-TT-tuftsin protein was prepared by prokaryotic expression and purification. BALB/c mice were immunized after mixed with aluminum adjuvant, and the humoral and cellular immune effects were evaluated. The recombinant S-TT-tuftsin protein was expressed as an inclusion body, and was purified by ion exchange chromatography and renaturated by gradient dialysis. The renaturated protein was identified by Dot blotting and reacted with serum of descendants immunized with SARS-CoV-2 subunit vaccine. The results showed that the antibody level reached a plateau after 35 days of immunization, and the serum antibody ELISA titer of mice immunized with recombinant protein containing intramolecular adjuvant was up to 1:66 240, which was significantly higher than that of mice immunized with S-RBD protein ( P < 0.05). At the same time, the recombinant protein containing intramolecular adjuvant stimulated mice to produce a stronger lymphocyte proliferation ability. The stimulation index was 4.71±0.15, which was significantly different from that of the S-RBD protein (1.83±0.09) ( P < 0.000 1). Intramolecular adjuvant tetanus toxin peptide and tuftsin peptide significantly enhanced the humoral and cellular immune effect of the SARS-CoV-2 S protein RBD domain, which provideda theoretical basis for the development of subunit vaccines for SARS-CoV-2 and other viruses.

Hepatitis B virus core protein (HBc) has become a hot spot in drug carrier protein research due to its natural particle self-assembly ability and ease of modification. The truncation of the C-terminal polyarginine domain (CTD, aa 151-183) of HBc does not affect the self-assembly of the particles. However, it does affect the internal and external charges of the particles, which may subsequently affect drug encapsulation. Thus, the truncated C-terminal polyarginine domain (CTD) of HBc and the inserted RGD peptide were selected to construct and express three HBc variants (RH) encapsulated with ICG (RH/ICG) with different C-terminal lengths to compare the stability and drug activity of their nanoformulations. RH160/ICG was found to have a great advantages in encapsulation efficiency and biological imaging. Compared with other HBc variants, RH160/ICG significantly improved encapsulation efficiency, up to 32.77%±1.23%. Cytotoxicity and hemolysis assays further demonstrated the good biocompatibility of RH160/ICG. Cell uptake and in vivo imaging experiments in mice showed that RH160/ICG could efficiently deliver ICG in tumor cells and tumor sites with good imaging effect. This research provides a new direction for further expanding the diagnosis and treatment application of ICG and development of HBc-based nanoparticle drug carrier platform.

Different fragments of SARS-CoV-2 nucleocapsid (N) protein were expressed and purified, and a fluorescence immunochromatography method for detection of SARS-CoV-2 total antibody was established. The effect of different protein fragments on the performance of the method was evaluated. The N protein sequence was analyzed by bioinformatics technology, expressed in prokaryotic cell and purified by metal ion affinity chromatography column. Different N protein fragments were prepared for comparison. EDC reaction was used to label fluorescence microsphere on the synthesized antigen to construct sandwich fluorescence chromatography antibody detection assay, and the performance was systemically evaluated. Among the 4 prepared N protein fragments, the full-length N protein (N419) was selected as the optimized coating antigen, N412 with 0.5 mol/L NaCl was used as the optimal combination; deleting 91-120 amino acids from the N-terminal of N412 reduced non-specific signal by 87.5%. the linear range of detection was 0.312-80 U/L, the limit of detection was 0.165 U/L, and the accuracy was more than 95%. A fluorescence immunochromatographic detection method for analysis of SARS-CoV-2 total antibody was established by pairing N protein fragments. The detection result achieved 98% concordance with the commercially available Guangzhou Wanfu test strip, which is expected to be used as a supplementary approach for detection of SARS-CoV-2. The assay could also provide experimental reference for improving the performance of COVID-19 antibody detection reagents.

With rapid urbanization, increasing amounts of chemicals are being used in our daily life. Emerging organic contaminants are a large class of chemicals that are widely detected in the environment. They include pharmaceuticals and personal care products, pesticides, perfluorinated compounds, and endocrine-disrupting compounds. Recently, many countries have reported the occurrence of emerging organic contaminants. In addition, emerging organic contaminants are frequently detected in various environmental samples, including river and lake water samples. Despite their low concentrations in the environment, emerging organic contaminants are potential risks to humans and wildlife. Because they could lead to endocrine disrupting effects and the occurrence of resistance genes. Thus, the detection of emerging organic contaminants in the environment is imperative for ecological systems and human health. The recent development of analytical techniques has led to the identification of more emerging organic contaminants in the environment. At present, the commonly used chromatographic separation techniques include liquid chromatography and gas chromatography. For the identification and quantitation of emerging organic contaminants, chromatography is usually combined with spectroscopy or mass spectrometry. The concentrations of emerging organic contaminants are not sufficiently high to be detected directly, and the matrix is complex in environmental samples. Emerging organic contaminants also have diverse properties. Thus, environmental samples must be pretreated before detection. Pretreatment includes the concentration and purification of the environmental samples. The commonly used pretreatment methods are ultrasound-assisted extraction, QuEChERS, liquid-liquid extraction, and solid-phase extraction. With the development of pretreatment methods, solid-phase microextraction and stirred-bar adsorption extraction have also become popular. These sample pretreatment methods have many advantages such as good efficiency and effectivity for recycling target compounds. Hence, they are widely used. However, these methods are time-consuming, in addition to requiring expensive consumables and large amounts of organic solvents. Lyophilization is a technique used for product dehydration, preservation, and storage in the agricultural and food industries. It is also occasionally used to simplify the extraction procedure for drug residue analysis. There are three stages of lyophilization: freezing, primary drying, and secondary drying. Lyophilization has many advantages when used for pretreatment, namely, operational simplicity, less consumables, less sample volume, prolonged storage, and minimal sample loss. Lyophilization is thus an alternative method for the pretreatment of emerging organic contaminants in environmental samples. Recently, lyophilization has been applied to the pretreatment of emerging organic contaminants in environmental water samples. In general, a few steps were included during sample analysis. First, the samples were pretreated and frozen before the primary drying stage. After lyophilization, the analytes were extracted using a small amount of organic solvent and dried with nitrogen. Consequently, the elution was reconstructed and detected after dryness and filtration. Many groups of emerging organic contaminants could be recovered, including antibiotics, pesticides, and endocrine-disrupting compounds. The lyophilization could be automated, so that minimal manual intervention was required. By adopting lyophilization, good recoveries and accuracies were achieved. A few cleanup processes were conducted, and a small amount of organic solvent was consumed. Thus, lyophilization is a highly prospective pretreatment method for monitoring emerging organic contaminants, and can be extended to a diverse range of these contaminants. For large-scale and high-frequency sampling campaigns, cheap and convenient pretreatment is urgently needed. In this study, typical emerging organic contaminants are described, along with the universal types of such contaminants and the principles of lyophilization. The application of lyophilization to the detection of emerging organic contaminants in the environment is also introduced. The future of lyophilization is discussed, which provides a reference for emerging contaminant detection in environmental samples.

A rapid and simple method to detect tumor markers in liver cancer was established by combining immunochromatography technique with fluorescent microsphere labeling. According to the principle of double antibody sandwich, the cytoskeleton-associated protein 4 (CKAP4) paired antibody was used as the labeled and coated antibody, and the goat anti-rabbit polyclonal antibody was used as the quality control line coated antibody in the preparation of the CKAP4 fluorescent immunochromatographic test strips. After the preparation, the test strips were evaluated on various performance indicators, such as linearity, precision and stability. The CKAP4 immunochromatographic strip prepared by time-resolved fluorescent microspheres had high sensitivity, and good specificity. Its precision was within 15%, recovery between 85% and 115%, and linear range between 25 and 1 000 pg/mL. The test strip could be kept stable at 37 °C for 20 days, and it correlated well with commercial ELISA kits. The CKAP4 fluorescence immunochromatography method can quantitatively detect the content of CKAP4 in serum. Furthermore, it is rapid, sensitive, simple, economical and single-person operation. This method has the potential of becoming a new method for the diagnosis and treatment of liver cancer.