Microfluidic paper-based chemiluminescence sensing platform based on functionalized CaCO3 for time-resolved multiplex detection of avian influenza virus biomarkers.

Multiplex detection can enhance diagnostic precision and improve diagnostic efficiency, providing important assistance for epidemiological investigation and epidemic prevention. There is a great need for multi-detection sensing platforms to accurately diagnose diseases. Herein, we reported a µPAD-based chemiluminescence (CL) assay for ultrasensitive multiplex detection of AIV biomarkers, based on three DNAzyme/Lum/PEI/CaCO3. Three time-resolved CL signals were sequentially generated with detection limits of 0.32, 0.34, and 0.29 pM for H1N1, H7N9, and H5N1, respectively, and with excellent selectivity against interfering DNA. The recovery test in human serum displayed satisfactory analysis capabilities for complex biological samples. The µPAD-based CL assay achieved multiplex detection within 70 s, with a high time resolution of 20 s. The proposed strategy has the advantages of low cost, high sensitivity, good selectivity, and wide time resolution, the µPAD-based CL assay has shown great potential in the early and accurate diagnosis of diseases.

Microbiome-friendly PS/PVP electrospun fibrous membrane with antibiofilm properties for dental engineering.

Dental caries is one of the most prevalent and biofilm-associated oral diseases in humans. Streptococcus mutans, with a high ability to form biofilms by adhering to hard surfaces, has been established as an important etiological agent for dental caries. Therefore, it is crucial to find a way to prevent the formation of cariogenic biofilm. Here, we report an electrospun fibrous membrane that could inhibit the adhesion and biofilm formation of S. mutans. Also, the polystyrene (PS)/polyvinyl pyrrolidone (PVP) electrospun fibrous membrane altered the 3D biofilm architecture and decreased water-insoluble extracellular polysaccharide production. Notably, the anti-adhesion mechanism which laid in Coulomb repulsion between the negatively charged PS/PVP electrospun fibrous membrane and S. mutans was detected by zeta potential. Furthermore, metagenomics sequencing analysis and CCK-8 assay indicated that PS/PVP electrospun fibrous membrane was microbiome-friendly and displayed no influence on the cell viability of human gingival epithelial cells and human oral keratinocytes. Moreover, an in vitro simulation experiment demonstrated that PS/PVP electrospun fibrous membrane could decrease colony-forming unit counts of S. mutans effectively, and PS/PVP electrospun fibrous membrane carrying calcium fluoride displayed better anti-adhesion ability than that of PS/PVP electrospun fibrous membrane alone. Collectively, this research showed that the PS/PVP electrospun fibrous membrane has potential applications in controlling and preventing dental caries.

Multifunctionalized flower-like gold nanoparticles with high chemiluminescence for label-free sensing of the hepatitis C virus core protein.

Developing functionalized nanomaterials with strong chemiluminescence (CL) properties is highly significant for ultrasensitive bioanalysis. Here, we report chitosan (CS), luminol, and Co2+-functionalized flower-like gold nanoparticles (Co2+/CS/Lum/AuNFs) with strong CL for the label-free sensing of the HCV core protein (HCVcp). The Co2+/CS/Lum/AuNFs exhibited a greatly enhanced CL emission at around 425 nm, which is 50 times stronger than that of CS/Lum/AuNFs, and is superior to other commonly reported CL nanomaterials. The HCVcp aptamer (HCVcp-apt) further functionalized the surface of the Co2+/CS/Lum/AuNFs through electrostatic interactions blocked the Co2+ catalytic site, depressing the CL. Owing to the high affinity of HCVcp for the HCVcp-apt, the presence of HCVcp predominated its binding and effectively separated the HCVcp-apt from the surface of the Co2+/CS/Lum/AuNFs, so that the CL intensity was significantly enhanced. As the results showed, the HCVcp-apt/Co2+/CS/Lum/AuNFs were successfully used to detect the HCVcp in human serum samples with a linear range from 0.50 ng mL-1 to 1.00 µg mL-1, a detection limit of 0.16 ng mL-1 and an excellent selectivity over other analogs. The strategy is universal for the development of the ultrasensitive detection of other proteins in the field of early disease diagnostics.

One-step fast and label-free imaging array for multiplexed detection of trace avian influenza viruses.

Rapid and low-cost diagnosis of multiple infectious diseases is of great significance especially in densely populated or resource-constrained settings. Herein, we developed a one-step fast and label-free imaging array for multiplexed detection of trace avian influenza virus (AIV) DNA biomarkers. By designing a series of specific and efficient catalytic hairpin assembly (CHA) amplification reactions and utilizing thioflavin T, a specific G-quadruplex fluorescence probe, three subtypes of AIV DNA biomarkers (H1N1, H7N9 and H5N1) were simultaneously and quickly detected within only 20 min, which just needed a small reagent volume of 50 µL and a smartphone instead of a spectrometer. With the combination of fluorescence imaging output and grey-level analysis, the array sensor can be on-site with the limit of detection of 136 pM, 141 pM and 129 pM for H1N1, H7N9 and H5N1, respectively. The imaging array also displayed good mismatch discrimination, excellent anti-interference, and real sample application. In view of its advantages of fast detection, low cost and multiplexed analysis, the imaging array is expected to have potential applications for early infectious disease diagnosis in resource-constrained settings.

[Plasma thromboxane A2 and prostaglandin I2 levels and their ratio in children with Henoch-Schonlein purpura nephritis].

OBJECTIVE: To study the changes and roles of plasma thromboxane A2 (TXA2) and prostaglandin I2 (PGT2) levels and their ratio in Henoch-Schonlein purpura nephritis (HSPN) in children. METHODS: Plasma levels of TXA2 and PGI2 were measured using ELISA in 45 children with HSPN and 20 healthy children. RESULTS: Plasma TXA2 level was significantly higher, while plasma PGI2 level was significantly lower in HSPN children in the acute phase than in the control (P<0.01). The ratio of TXA2/PGI2 in HSPN children in the acute phase was statistically higher than in the control (9.55+/-3.56 vs 0.87+/-0.21; P<0.01). In the convalescence phase, plasma TXA2 level remained higher and plasma PGI2 level was elevated and higher than in the control, so the ratio of TXA2/PGI2 was reduced to normal level. CONCLUSIONS: The imbalance of TXA2 and PGI2 may be involved in the development of renal damage in children with HSPN. The balance of TXA2 and PGI2 contributes to renal recovery.