BioChip Journal最新文献

This study presents a novel method for detecting plant viruses by combining a personal glucose meter (PGM)-based cascade enzymatic reaction (CER) with loop-mediated isothermal amplification (LAMP). This technique exploits the consumption of deoxynucleotides (dNTPs) during the LAMP process as a substrate for CER, leading to a measurable change in glucose concentration. This change can be detected using PGM, enabling the identification of the presence or absence of the target virus. This method provide a more efficient alternative to traditional methods like ELISA and PCR. It overcomes their limitation in terms of laboratory equipment requirement, sensitivity, and on-site applicability. In addition, we also developed a portable diagnostic device that integrates a heating block with a glucose measurement module. By utilizing this device, the rapid and precise detection of various plant viruses, including horseradish latent virus (HRLV), onion yellow dwarf virus (OYDV), soybean yellow common mosaic virus (SYCMV), cnidium vein yellowing virus 1 (CnVYV-1), and perilla mosaic virus (PerMV), successfully achieved within 40 min. This advancement offers a practical and cost-effective solution for managing plant pathogen threats in agriculture.

Thermal gradients have emerged as a promising technique for manipulating and sorting biological material at the microscale, holding considerable potential in lab-on-a-chip technology. Herein, we propose a non-invasive thermohydrodynamic approach for fast cell manipulation using a microfluidic open-to-air device. Cell discrimination is achieved by simply changing the temperature gradient toward the control of the convective effect on their displacement. First, the size and morphology/roughness-based motion capabilities were modeled using polystyrene (PS) microparticles with different sizes (5 and 20 μm) and polycaprolactone (PCL) microspheres, respectively. Computational fluid dynamics simulations of the generated flow were also carried out to demonstrate the influence of both the thermohydrodynamic and Marangoni effects in the PS particle displacement, where the thermally induced convective effect was not enough to move the microparticles inside the channel, but the combination of thermally induced convection together with the Marangoni effect. Indeed, small particles (5 μm) followed a full convective path, whereas the bigger ones (20 μm) exhibited a rolling motion on the substrate from the cold side to the hot side. Also, the relationship between in-flow speed and PCL (≈ 20 μm) surface roughness confirmed the driving force of this convection-based approach. Then, the microfluidic device was successfully used to separate Henrietta Lacks cancer cells (HeLa) from red blood (RBCs) and fibroblast (HFF-1) cells. To this end, thermal gradients were tailored to achieve the desired thermohydrodynamic effect, showing a highly versatile performance. Both cell models (HeLa-RBCs and HeLa-HFF-1), due to rationale tweaking of the imposed temperature gradients (ΔT = 10 K, 303–293 K, and ΔT = 5 K, 303–298 K), were efficiently separated in less than 5 and 60 s, respectively; with excellent cell viabilities. The proposed microfluidic approach holds considerable promise for thermohydrodynamic sorting and manipulation of biological material by non-invasive methods using portable instrumentation. The potential parallelization of the thermal-convective approach opens new avenues for early disease diagnosis (liquid biopsies) or the study of biological systems, even at physiological temperatures with a potential impact in cell (organ)-on-a-chip technologies.

DNA has emerged as an attractive medium for storing large amounts of data due to its high information density, long-term stability, and low energy consumption. However, in contrast to commercially available storage media, DNA-based data storage currently falls behind in terms of writing and reading speeds, waste as well as cost. To harness the full potential of DNA as a data storage medium, it is imperative to advance high-throughput DNA synthesis without compromising cost and pollution. Industry-standard phosphoramidite DNA synthesis has reached its limitation because of its short nucleotide length (< 200), overconsumption of organic solvents leading to the production of toxic wastes, and slow writing speed. Enzymatic DNA synthesis shows promise as a replacement with long nucleotides, an environmentally friendly process, and fast writing speed. In this review, we overview enzymatic DNA synthesis methods, evaluate current methods that utilize high-throughput and parallel synthesis, and conclude with comments on how enzymatic DNA synthesis can be the answer to DNA data storage.

Veterinary drug residues in food have emerged as an urgent threat to consumer safety. Herein, we present the first square wave voltammetric method for the trace-level detection of cinnarizine residues, a recently used antischistosomal drug, in bovine food samples. The method depends on the electrochemical oxidation after modification of the carbon paste sensor with recycled Al₂O₃-NPs functionalized multi-walled carbon nanoparticles. The produced sensor (Al₂O₃-NPs/ MWCNTs/CPE) was characterized using the transmission electron microscope, scanning electron microscope, Fourier-transform infrared spectroscopy, energy-dispersive spectrometer, and X-ray diffractometer that confirm the successful incorporation of the Al₂O₃-NPs/MWCNTs composite into the modified electrode. As expected, the active surface area and electron transfer processes were accelerated by the modification, which was evidenced by cyclic voltammetry, chronoamperometric studies, scan rate studies, and electrochemical impedance spectroscopy. Compared to previous techniques, this facile sensor demonstrated enhancements across critical analytical criteria including the detection limit of 0.17 nM, linear response across 5–100 nM (r² = 0.998), accuracy ranging from 96.5 to 103.2%, precision below 0.81% relative standard deviation, reproducibility within 0.36% range, 20 s response time and applicability in spiked food matrices. In addition, five different greenness and whiteness tools quantified exceptional environmental friendliness, economic feasibility and waste reduction of 63%–93%, reaffirming alignment with sustainability paradigms. These advantages support practical adoption in quality control especially laboratories lacking expensive instrumentation. Overall, the ingenious sensor reconciles nanotechnology innovation with the circular economy ethos to tackle an urgent food safety challenge, guided holistically by sustainability metrics.

Lateral flow immunoassay (LFIA) has become a popular method for the rapid detection of biological molecules, with an emerging need for multiplex detection capabilities. A novel LFIA device capable of simultaneously detecting three different antigens on a single test line was developed, with each antigen identifiable by a unique color. Gold nanoparticles (AuNPs; red), gold nanorods (AuNRs; blue), and silver nanoparticles (AgNPs; yellow) were engineered to flow concurrently within the LFIA device and specifically react with α-fetoprotein (AFP), neuron-specific enolase (NSE), and carcinoembryonic antigen (CEA) on the test line. The device was effective for both individual and simultaneous detection of the analytes, with a limit of detection (LOD) of 50 ng/mL. Given its rapid response, ease of use, and affordability, this multiplex detection LFIA device shows great potential for a wide range of applications, including food quality management, livestock diagnosis, and health and environmental monitoring.

Abstract

The contagious respiratory illness coronavirus disease 2019 (COVID-19) has had an unprecedented impact on both global health and society, causing a global pandemic due to its rapid transmission. The emergence of numerous variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) underscores the critical importance of accurately diagnosing variants of concern (VOCs). Viruses have demonstrated a remarkable ability to evolve and adapt to their environments. Therefore, it is crucial to develop effective diagnostic methods that provide rapid, high sensitivity, and selectivity in a point-of-care (PoC) format, meeting the vital need for detecting and addressing emerging new viruses in the future. With the development of nanotechnology and biotechnology, there have been innovations in rapid, multiplexed, and portable sensors with high sensitivity and specificity. In this review, we discuss the fundamental properties of the SARS-CoV-2 virus, conventional diagnostic methods, and recent developments from the perspective of electrochemical- and nanophotonic-based SARS-CoV-2 biosensors, including our recent work.

Flow at various scales, such as perfusion flow and interstitial flow, is a critical component of the physiology of living systems. Microphysiological system (MPS), which is designed to mimic human physiology, needs to recapitulate various physiological flows to accurately reflect in vivo conditions. Most MPSs that simulate flows utilize a pump and tubing (pumped-based-flow MPS). However, these components have limitations that prevent them from recapitulating sophisticated physiological phenomena. Alternatively, passive-flow MPS can be used to recapitulate physiological flow on various scales without using pumps or tubing. This review presents recent developments in passive-flow-based MPS using various engineering approaches. To this end, engineering approaches that enable a passive-flow-based MPS to operate are summarized. Subsequently, representative examples of passive-flow-based MPS are reviewed under the criterion of whether they can recapitulate single-organ (tissue) or multi-organ (tissue) systems. It is our belief that passive-flow-based MPS will be widely used in a wide range of fields, such as human physiology research, analysis of pharmacokinetics and pharmacodynamics (PK/PD), and even space medicine research.

Among human CD8⁺ T cells, senescent cells are marked by the expression of CD57. The frequency of senescent CD57⁺CD8⁺ T cells is significantly correlated with aging and age-associated disorders, and it can be measured by multi-color flow cytometry. However, multi-color flow cytometry presents challenges in terms of accessibility and requires significant resource allocation. Therefore, developing a rapid and straightforward method for quantifying CD57⁺CD8⁺ T cells remains a key challenge. This study introduces a microfluidic device composed of a PDMS microfluidic channel with a pre-modified glass substrate for anti-CD8 antibody immobilization. This design allows blood samples to flow through, enabling the selective capture of CD8⁺ T cells while minimizing the required blood sample volume. This technology enables accurate and reliable quantification of CD57⁺ cells among captured CD8⁺ T cells through fluorescence image analysis. The ability of the device to easily quantify senescent CD57⁺CD8⁺ T cells is anticipated to contribute significantly to both immunological research and clinical applications.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (NP) participates in viral genome packaging and abundantly produced when infected. In this work, SPR biosensor for the detection of SARS-CoV-2 in viral fluid using Fv-antibodies with the binding affinity to nucleocapsid protein (NP) of SARS-CoV-2. The F_V-antibodies with a specific binding activity to the SARS-CoV-2 NP were screened using the F_V-antibody library, which was expressed on the outer membrane of E. coli. F_V-antibodies comprised three complementarity-determining regions (CDRs) and four frame regions (FRs) of the heavy chain at the binding pocket of IgG. The F_V-antibody library was prepared by performing site-directed mutagenesis and by using the autodisplay technology; F_V-antibodies with specific binding activities to the nucleocapsid protein (NP) of SARS-CoV-2 were screened using NP-immobilized magnetic beads. First, E. coli isolates with the target F_V-antibody were screened, and the binding affinity (K_D) was estimated for the screened E. coli clones using FACS analysis. Then, the outer membrane (OM) of the screened E. coli clones with autodisplayed Fv-antibodies was obtained and layered on an SPR biosensor, and the binding curves of four different coronavirus (CoV) culture fluids, SARS-CoV-2, SARS-CoV, MERS-CoV, and CoV strain 229E, were compared. Finally, the F_V-antibodies of the screened E. coli clones were synthesized as peptides (11 amino acid residues), and the binding constants (K_D) to NP as well as the binding curves of the CoV strains in culture fluids were estimated. Using docking simulation, binding sites and interaction types between NP and each synthetic peptide were investigated.

Graphical Abstract

Abstract

Due to its similarity to in vivo conditions, tumor spheroids are actively used in research areas, such as drug screening and cell–cell interactions. A substantial quantity of spheroids is crucial for obtaining dependable results in high-throughput screening. Conventional fabrication methods of spheroid have limitations in low yield and morphological variation. Droplet-based microfluidic system capable of mass-producing uniformed spheroids can overcome these limitations. In this study, we investigated the optimal culture conditions, which allows to researchers provide guidelines for producing spheroids with the desired diameter and quantity. Mass-produced spheroids were employed to analyze compaction, which is crucial for evaluating the remission effects of drugs, as well as the formation of a necrotic core, which induces a bias in the analysis of drug response and viability. The time point at which compaction is completed and the diameter begins to increase was measured using spheroids with diameters of both > 400 μm and < 400 μm, and spheroids do not proliferate a linear growth trend. Spheroid with diameters ranging from 73.4 ± 11.42 μm to 371 ± 5.11 μm was used to predict the formation of the necrotic core based on live cell counting, and diameter of 300–330 μm was mathematically calculated as the diameter where a necrotic core forms. Additionally, the use of artificial intelligence (AI) for high-throughput analysis is crucial for obtaining time-saving and reproducible data. We produced BT474 and MCF-7 spheroids with diameters of 100, 200, and 300 μm and obtained morphological indicators from an AI-based program to compare the differences in heterogeneous breast tumor spheroids. Through this study, we optimized the diameter of spheroids and the initiation timing for drug screening and emphasized the importance of AI-based morphological analysis in high-throughput screening.