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As an acute inflammatory response, sepsis may cause septic shock and multiple organ failure. Rapid and reliable detection of pathogens from blood samples can promote early diagnosis and treatment of sepsis. However, traditional pathogen detection methods rely on bacterial blood culture, which is complex and time-consuming. Although pre-separation of bacteria from blood can help with the identification of pathogens for diagnosis, the required low-velocity fluid environment of most separation techniques greatly limits the processing capacity for blood samples. Here, we present an acoustofluidic device for high-throughput bacterial separation from human blood cells. Our device utilizes a serpentine microfluidic design and standing surface acoustic waves (SSAWs), and separates bacteria from blood cells effectively based on their size difference. The serpentine microstructure allows the operating distance of the acoustic field to be multiplied in a limited chip size via the "spatial multiplexing" and "pressure node matching" of SSAW field. Microscopic observation and flow cytometry analysis shows that the device is helpful in improving the flow rate (2.6 μL min-1 for blood samples; the corresponding velocity is ∼3 cm s-1) without losing separation purity or cell recovery. The serpentine microfluidic design provides a compatible solution for high-throughput separation, which can synergize with other functional designs to improve device performance. Further, its advantages such as low cost, high biocompatibility, label-free separation and ability to integrate with on-chip biosensors are promising for clinical utility in point-of-care diagnostic platforms.

We present an on-chip optical biosensor for the detection of COVID-19. The subwavelength grating waveguide-based micro-ring resonator with high sensitivity and low limit of detection integrates with microfludic channel, which promises clinical utility in point-of-care diagnostic.

The enrichment of Escherichia coli (E. coli) is of great significance for detection of E. coli species. In this paper, the principle of vortex velocity field generated by BAW resonator is analyzed. A hand-held device with simple operation and small size, which can quickly enrich E. coli, has been demonstrated. High efficient enrichment of E. coli in flowing samples can be achieved by using the vortex field array generated by the GHz BAW resonator array, and the whole collecting process can be completed in one minute. In addition, the experimental results show that the trapping rate of E. coli can reach 89%.

Controllable cell lysis is a crucial step for the intracellular detection, and has the potential to be applied to cell transfection. This work demonstrates a new device of acoustic pillar array chip for the parallel trapping and controllable lysis of cells. Through vibrating pillars, acoustic wave is coupled into the fluid. Radiation force and streaming field with great velocity gradient are triggered near the pillar. Cells are trapped under the radiation force and lysed by the gradient induced shear stress. Using acoustic pillar array chips, red blood cells are demonstrated to be lysed efficiently in a controllable manner.

Exposure to trace amounts of lead is known to harm human health, especially for children, which results in irreversible detriment to brain and nerve development. However, most of the sensor platforms using the colorimetric method to detect lead (II) ions (Pb2+) are difficult to reach a decent limit of detection (LOD) and a large detection range. This work presents a practical method to detect Pb2+ in aqueous-medium with the help of single-particle dark field spectroscopy, which allows us to obtain good LOD and wide detection range. Our results illustrate that the glutathione functionalized AuNPs are able to capture free AuNPs in the presence of Pb2+ to form multipliers. Such a process results in a significant spectral redshift of scattering spectra due to plasmonic coupling, which allows us to reach a good LOD of 3.5 pM, and a large linear quantifiable detection range from 10 pM to 10 μM. The performance of our sensor platform provides an alternative way to detect traces of Pb2+ in real-life water samples.

The conversion of arachidonic acid into prostaglandins by cyclooxygenase (COX)-2 contributes to the biological properties of malignant tumours. During the initiation and development of various tumours, the Notch family plays a key role. However, the association between COX-2 and the Notch family in gastric cancer (GC) remains unclear. The present study aimed to clarify the mechanisms through which COX-2 participates in the pathogenesis of GC. Quantitative PCR and western blot analysis were used to detect the expression of Notch family members and COX-2 in human GC and paracancerous tissues, GES-1 cells and GC cell lines (AGS, SGC-7901, BGC-823, and MGC-803) treated with or without celecoxib, prostaglandin E2 and small interfering RNA (siRNA). A CCK-8 assay was performed to detect the proliferation of GC cells transfected with siRNA against COX-2 (si-COX-2). A high mRNA expression of Notch1 and a decreased expression of Notch-1 intracellular active domain (N1IC) in GC were found to be related to the depth of invasion and TNM staging. The mRNA levels of Notch2, Notch3, Jagged1 and N2IC were found to be high in GC. A High expression of COX-2 was associated with poorly differentiated and deeply invasive GC. COX-2 and Notch1 exhibited an inverse expression pattern in the GES-1 cells and different GC cell lines; the inhibition of COX-2 increased Notch1 expression and activated the GC cells, whereas Notchl downregulation had the opposite effect. Notchl exhibited varying effects on Snail in the GC cell lines. The downregulation of COX-2 expression significantly inhibited the proliferation of GC cells. On the whole, the expression of Notch signalling molecules differed in GC. COX-2 inversely regulated Notchl in GC and partially depended on the Notchl signalling pathway in altering the expression of Snail.