The assembly of colloidal particles into micro-patterns is essential in optics, informatics, and microelectronics. However, it is still a challenge to achieve quick, reversible, and precise assembly patterns within micro-scale spaces like droplets. Hereby, a method is presented that utilizes in-plane dielectrophoresis to precisely manipulate particle assemblies within microscale droplets.
View Article and Find Full Text PDFBiomicrofluidics
May 2024
Antimicrobial resistance is getting serious and becoming a threat to public health worldwide. The improper and excessive use of antibiotics is responsible for this situation. The standard methods used in clinical laboratories, to diagnose bacterial infections, identify pathogens, and determine susceptibility profiles, are time-consuming and labor-intensive, leaving the empirical antimicrobial therapy as the only option for the first treatment.
View Article and Find Full Text PDFPower ultrasound is widely used in industrial production, medical equipment, aerospace, and other fields. Currently, there are two main types of commonly used power generation devices: piezoelectric ultrasonic transducers and magnetostrictive ultrasonic transducers. However, in certain situations with limited external dimensions, the applications of existing power ultrasound devices are limited.
View Article and Find Full Text PDFThe culture-based methods for viable Escherichia coli (E. coli) detection suffer from long detection time and laborious procedures, whereas the molecule tests and immune recognition technologies lack live/dead E. coli differentiation.
View Article and Find Full Text PDFBackground: The identification and quantification of viable Escherichia coli (E. coli) are important in multiple fields including the development of antimicrobial materials, water quality, food safety and infections diagnosis. However, the standard culture-based methods of viable E.
View Article and Find Full Text PDFBackground: The empirical antibiotic therapies for bacterial infections cause the emergence and propagation of multi-drug resistant bacteria, which not only impair the effectiveness of existing antibiotics but also raise healthcare costs. To reduce the empirical treatments, rapid antimicrobial susceptibility testing (AST) of causative microorganisms in clinical samples should be conducted for prescribing evidence-based antibiotics. However, most of culture-based ASTs suffer from inoculum effect and lack differentiation of target pathogen and commensals, hampering their adoption for evidence-based antibiotic prescription.
View Article and Find Full Text PDFRapid antimicrobial susceptibility testing (AST) with the ability of bacterial identification is urgently needed for evidence-based antibiotic prescription. Herein, we propose an enzymatic AST (enzyAST) that employs β-d-glucuronidase as a biomarker to identify pathogens and profile phenotypic susceptibilities simultaneously. EnzyAST enables to offer binary AST results within 30 min, much faster than standard methods (>16 h).
View Article and Find Full Text PDFMulti-color two-photon microscopy imaging of live cells is essential in biology. However, the limited diffraction resolution of conventional two-photon microscopy restricts its application to subcellular organelle imaging. Recently, we developed a laser scanning two-photon non-linear structured illumination microscope (2P-NLSIM), whose resolution improved three-fold.
View Article and Find Full Text PDFEmpirical antibiotic therapies are prescribed for treating uncomplicated urinary tract infections (UTIs) due to the long turnaround time of conventional antimicrobial susceptibility testing (AST), leading to the prevalence of multi-drug resistant pathogens. We present a ready-to-use 3D microwell array chip to directly conduct comprehensive AST of pathogenic agents in urine at the single-cell level. The developed device features a highly integrated 3D microwell array, offering a dynamic range from 10 to 10 CFU mL, and a capillary valve-based flow distributor for flow equidistribution in dispensing channels and uniform sample distribution.
View Article and Find Full Text PDFThe urinary tract infections by antibiotic-resistant bacteria have been a serious public health problem and increase the healthcare costs. The conventional technologies of diagnosis and antimicrobial susceptibility testing (AST) relying on multiple culture-based assays are time-consuming and labor-intensive and thus compel the empirical antimicrobial therapies to be prescribed, fueling the prevalence of antimicrobial resistance. Herein, we propose an all-in-one viability assay in an enclosed 3D microwell array chip, termed digital β-d-glucuronidase (GUS)-AST assay.
View Article and Find Full Text PDFTraditionally, comprehensive laboratorial experiments on newly proposed microfluidic devices are necessary for theoretical validation, technological design, methodological calibration and optimization. Multiple parameters and characteristics, such as the flow rate, particle size, microchannel dimensions, , should be studied by controlled trials, which could inevitably result in extensive experiments and a heavy burden on researchers. In this work, a novel numerical model was introduced to simulate particle migration within a complicated double-layered microchannel.
View Article and Find Full Text PDFBiomicroparticles such as proteins, bacterium, and cells are known to be viscoelastic, which significantly affects their performance in microfluidic applications. However, the exact effects and the quantitative study of cellular viscoelastic creep within different applications remain unclear. In this study, the cellular-deforming evolution within a filter unit was studied using a multiphysics numerical model.
View Article and Find Full Text PDFRapid and sensitive Escherichia coli (E. coli) detection is important in determining environmental contamination, food contamination, as well as bacterial infection. Conventional methods based on bacterial culture suffer from long testing time (24 h), whereas novel nucleic acid-based and immunolabelling approaches are hindered by complicated operation, the need of complex and costly equipment, and the lack of differentiation of live and dead bacteria.
View Article and Find Full Text PDFFood poisoning and infectious diseases caused by () are serious public health concerns for human health and food safety. The diversity and complexity of food matrices pose great challenges for rapid and ultra-sensitive detection of in food samples. A method capable of identification, detection, and quantification of is essential for addressing these issues.
View Article and Find Full Text PDFThe rapid and accurate detection of viable bacteria is of great importance in food quality monitoring and clinical diagnosis. () is a major pathogenic bacterium, which causes potential threats to food safety and human health. Therefore, rapid and portable methods for preventing outbreaks are needed.
View Article and Find Full Text PDFDepression has been considered the most dominant mental disorder over the past few years. To help clinicians effectively and efficiently estimate the severity scale of depression, various automated systems based on deep learning have been proposed. To estimate the severity of depression, i.
View Article and Find Full Text PDFCarbon-based materials have been studied for their antimicrobial properties. Previously, most antimicrobial studies are investigated with suspended nanoparticles in a liquid medium. Most works are often carried out with highly ordered pyrolytic graphite.
View Article and Find Full Text PDFAn enzyme assay based method in a microfluidic slipchip was proposed for the rapid and label-free detection of E. coli. The specific target analyte of E.
View Article and Find Full Text PDFThe current outbreak of the coronavirus disease-19 (COVID-19) pandemic worldwide has caused millions of fatalities and imposed a severe impact on our daily lives. Thus, the global healthcare system urgently calls for rapid, affordable, and reliable detection toolkits. Although the gold-standard nucleic acid amplification tests have been widely accepted and utilized, they are time-consuming and labor-intensive, which exceedingly hinder the mass detection in low-income populations, especially in developing countries.
View Article and Find Full Text PDFACS Appl Mater Interfaces
February 2021
Matrix metalloproteinases (MMPs) play an important role in tumor progression. The study of dynamic MMPs activity at the single-cell level can dissect tumor heterogeneity in the time domain and facilitate finding out more efficient clinical solutions for tumor treatment. Due to the fluidity of the carrier oil, the existing droplet-based methods for single-cell MMP analysis rarely have the capability to track proteolytic assays in droplets continuously.
View Article and Find Full Text PDFCirculating tumor DNA (ctDNA) is a promising biomarker for tumor genotyping and therapy monitoring. Herein, we developed a digital PCR chip with embedded microwell and bidirectional partition network for highly sensitive ctDNA analysis. The embedded microwell contributes to increasing microreaction density (up to 7000 microwells/cm) and reducing evaporation during amplification.
View Article and Find Full Text PDFDigital PCR (dPCR) is a powerful technique capable of absolute quantification of nucleic acids with good accuracy. Droplet-based dPCR (ddPCR), among others, is one of the most important dPCR techniques. However, the surface tension-controlled droplets may suffer from fusion/fission due to the vigorous temperature change in PCR thermal cycling.
View Article and Find Full Text PDFThe quantification of low concentration proteins can facilitate the discovery of some significant biomarkers, and provide us a more profound understanding of cell heterogeneity when applied to single cell analysis. However, most state-of- art single cell protein detection platforms are bulky, expensive and complicated. Here we report a simple and low cost microfluidic dPCR (digital polymerase chain reaction) chip-based proximity ligation assay (PLA) for the quantification of low concentration proteins.
View Article and Find Full Text PDFA novel microfluidic chip employing power-free polydimethylsiloxane (PDMS) femtoliter-sized arrays was developed for the detection of low concentrations of protein biomakers by isolating individual paramagnetic beads in single wells. Arrays of femtoliter-sized wells were fabricated with PDMS using well-developed molding techniques. Paramagnetic beads were functionalized with specific antibodies to capture the antigens.
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