Disposable Chip Research Articles

Highly scalable design of 3D copper-doped graphene printed microfluidic chip for the electrochemical quantification of plasma homocysteine

Elevated levels of plasma homocysteine (Hcy) increase the risk of various diseases, but early diagnosis and monitoring can help prevent and treat such diseases. However, current diagnostic assays that quantify Hcy levels fail to detect more complex and rare proteins related to certain mutations, i.e., N-homocysteinylated proteins (N-Hcy-proteins), which are important for clinical decision-making. Therefore, the discrete diagnosis of Hcy in each mutated protein is in high demand. In this study, we design and fabricate a disposable microfluidic Hcy sensor chip (MHS-chip). Specifically, we utilize a laser direct-writing carbonization approach to mount a microfluidic channel filled with three-dimensional Cu-doped graphene and sensing electrodes onto a polyimide film for the first time. This microfluidic channel promotes the binding of N-Hcy-proteins and isolates the Hcy from a 10 µL plasma sample, while the sensing electrode is used for detection. The MHS-chip has a linear dynamic range of 0.01–124 µM and a detection limit of 2.9 nM, which is suitable for clinical application. Moreover, it exhibits good selectivity, high reproducibility, and real-time applicability in plasma samples. Overall, the MHS-chip is an efficient, low-cost device for the early diagnosis of Hcy and can be applied in point-of-care tests.

Fast analysis of Staphylococcus aureus in food products using disposable label-free nano-electrochemical immunosensor chips

Rapid analysis and early detection of food poisoning has become an important factor for the recognition and prevention of problems associated with food safety and public health. Accordingly, a number of different methods have been developed and applied for the detection and identification ofS. aureus. However, these methods are not suitable for on-site applications as they are time-consuming and laborious. Thus, a label-free impedimetric immunosensor was constructed using the self-assembling monolayer formation of the lipoic at the AuNPs@Fe3O4-screen printed electrode. The formed layer of the lipoic acid supported the covalent immobilization of anti-S. aureusantibody as the selective bio-recognition element. As a result, a specific immune reaction between the whole pathogen cells and the immobilized antibody was monitored under optimized conditions. Electrochemical impedance spectroscopy along with other chemical assessments were used to verify the stepwise assembly of the immunosensor fabrication. Accordingly, the newly developed impedimetric immunosensor showed high sensitivity and selectivity towards the targeting bacterial strain with the limit of detection and limit of quantification of 0.10, and 0.34 CFU/mL, respectively. Eventually, the designed immunosensor was successfully implemented to analyze theS. aureus contamination in milk and meat samples, whereas the obtained results were validated.

Acoustofluidic control of chemical concentration within picoliter droplets in a disposable microfluidic chip

We propose an acoustofluidic method to dynamically control the chemical concentration (CC) within picoliter-scale droplets at high-throughput production exceeding 2000 drops per second. Co-flowing laminar streams of two fluids were rapidly mixed via acoustic streaming flow-induced micro-vortices, and the mixing index was precisely controlled by modulating the wave amplitude. The mixed aqueous sample was fed into a T-junction as a dispersed phase with a continuous phase oil to produce droplets. We conducted numerical and experimental analysis on the flow mixing in terms of the flow rate and wave amplitude. We produced the droplets with tunable CCs with higher than 100-fold enhancement and the droplet libraries with varying inter-droplet chemical concentration (CCD) gradients. The temporal stability and dynamic controllability of the CCD were also verified by the experiments. We demonstrated the applicability of the proposed method by generating doxorubicin-loaded droplets with tunable CCs. The proposed device includes a disposable microfluidic chip to enable the reusable transducer on the piezoelectric substrate, leading to improved flexibility and functionality. We expect that the proposed method to produce droplet libraries with desired CCs is promising for various droplet microfluidic applications including high-through drug screening and discovery, combinatorial biochemistry, and synthesis of functionalized hydrogels.

High-throughput microbead assay system with a portable, cost-effective Wi-Fi imaging module, and disposable multi-layered microfluidic cartridges for virus and microparticle detection, and tracking.

In recent years biomedical scientific community has been working towards the development of high-throughput devices that allow a reliable, rapid and parallel detection of several strains of virus or microparticles simultaneously. One of the complexities of this problem lies on the rapid prototyping of new devices and wireless rapid detection of small particles and virus alike. By reducing the complexity of microfluidics microfabrication and using economic materials along with makerspace tools (Kundu et al. 2018) it is possible to provide an affordable solution to both the problems of high-throughput devices and detection technologies. We present the development of a wireless, standalone device and disposable microfluidics chips that rapidly generate parallel readouts for selected, possible virus variants from a nasal or saliva sample, based on motorized and non-motorized microbeads detection, and imaging processing of the motion tracks of these beads in micrometers. Microbeads and SARS-CoV-2 COVID-19 Delta variant were tested as proof-of-concept for testing the microfluidic cartridges and wireless imaging module. The Microbead Assay (MA) system kit consists of a Wi-Fi readout module, a microfluidic chip, and a sample collection/processing sub-system. Here, we focus on the fabrication and characterization of the microfluidic chip to multiplex various micrometer-sized beads for economic, disposable, and simultaneous detection of up to six different viruses, microparticles or variants in a single test, and data collection using a commercially available, Wi-Fi-capable, and camera integrated device (Fig. 1).

A disposable edoxaban sensor chip using carbon paste electrode grafted with molecularly imprinted polymer.

Although direct oral anticoagulants (DOACs) are generally safe and TDM is not required, blood levels of the drug are important information for response decisions in emergency care. In this study, an attempt was made to develop a disposable sensor chip for the rapid detection of edoxaban in blood, a type of DOAC. Molecularly imprinted polymers with edoxaban tosilate as a template and sodium p-styrene sulfonate as a functional monomer were grafted onto the surface of graphite particles, mixed with silicon oil dissolved in ferrocene to form a paste, and filled onto a substrate made of plastic film. Sensor chips were fabricated. The current obtained from this sensor by voltammetry within 150s depended on the edoxaban concentration. Sensitivity to edoxaban was also confirmed in bovine whole blood. The potential of disposable sensors to rapidly detect edoxaban in whole blood was demonstrated in this study, although selectivity, reproducibility, and sensitivity need to be improved for practical use.

Designing and fabrication of electrochemical nano-biosensor for the fast detection of SARS-CoV-2-RNA

SARS-CoV-2 caused a global panic among populations. Rapid diagnostic procedures for the virus are crucial for disease control. Thus, the designed signature probe from a highly conserved region of the virus was chemically immobilized onto the nanostructured-AuNPs/WO3-screen printed electrodes. Different concentrations of the matched oligonucleotides were spiked to test the specificity of the hybridization affinity whereas the electrochemical impedance spectroscopy was used for tracking the electrochemical performance. After a full assay optimization, limits of detection and quantification were calculated based on linear regression and were valued at 298 and 994 fM, respectively. Further, the high performance of the fabricated RNA-sensor chips was confirmed after testing the interference status in the presence of the mismatched oligos in one nucleotide and completely one. Worthy to mention that the single-stranded matched oligos can be hybridized to the immobilized probe in 5 min at room temperature. The designed disposable sensor chips are capable of detecting the virus genome directly. Therefore, the chips are a rapid tool for SARS-CoV-2 detection.

Disposable Sensor Chips with Molecularly Imprinted Carbon Paste Electrodes for Monitoring Anti-Epileptic Drugs.

Epilepsy is a neurological disorder that affects millions of people worldwide. Anti-epileptic drugs (AEDs) are critical for their management. However, the therapeutic window is narrow, and traditional laboratory-based therapeutic drug monitoring (TDM) methods can be time consuming and unsuitable for point-of-care testing. To address this issue, we developed a disposable sensor chip based on molecularly imprinted polymer-modified carbon paste electrodes (MIP-CPs) for the TDM of AEDs such as phenobarbital (PB), carbamazepine (CBZ), and levetiracetam (LEV). In this work, functional monomers (methacrylic acid) and crosslinking monomers (methylene bisacrylamide and ethylene glycol dimethacrylate) were copolymerized in the presence of the AED template and grafted on the graphite particles by simple radical photopolymerization. The grafted particles were mixed with silicon oil, dissolving ferrocene as a redox marker to make the MIP-carbon paste (CP). Disposable sensor chips were fabricated by packing the MIP-CP into the base made of poly (ethylene glycol terephthalate) (PET) film. The sensor's sensitivity was determined using differential pulse voltammetry (DPV), carried out on a single sensor chip for each operation. Linearity was obtained from 0-60 μg/mL in PB and LEV and 0-12 μg/mL in CBZ, covering their respective therapeutic range. The time taken for each measurement was around 2 min. The experiment using whole bovine blood and bovine plasma indicated that the existence of species that interfered had a negligible effect on the test's sensitivity. This disposable MIP sensor provides a promising approach for point-of-care testing and facilitating the management of epilepsy. Compared with existing tests, this sensor offers a faster and more accurate way to monitor AEDs, which is crucial for optimizing therapy and improving patient outcomes. Overall, the proposed disposable sensor chip based on MIP-CPs represents a significant advancement in AED monitoring, with the potential for rapid, accurate, and convenient point-of-care testing.

Comparison of Reproductive Outcomes in ICSI Cycles Using Sperm Chip Technique and Density Gradient Technique in Men with Normal Semen Analysis

Background: Microfluidic sperm sorting procedure or sperm chip technique is a chemical-free method of selecting sperm using a disposable chip. It is a new gentle alternative for sperm processing which has been produced to obtain sperm with higher rates of motility and better morphology, as well as to reduce DNA fragmentation in sperm with high DNA fragmentation to nearly undetectable levels. We aimed to evaluate sperm chip techniques on clinical pregnancy rates in patients who underwent intracytoplasmic sperm injection (ICSI). Methods: The patients in whom fresh embryo transfer (ET) on Day-3 or 5 after ICSI had been performed were analyzed in this prospective randomized cohort study. Results: Of those, 102 patients underwent ICSI with sperm isolated using sperm chip technique (study group) while 111 patients underwent ICSI with sperm isolated using swim-up technique (control group). No significant difference was observed between the groups in terms of fertilization rate in patients who underwent ET on the 3rd or 5th day. In the patients having ET on Day-3, Grade 1 embryos were obtained similarly between the sperm chip group and the control group. Grade 1 embryos transferred on Day-5 were observed significantly more frequently in the study group (p = 0.050). However, clinical pregnancy rates did not show significant differences between the groups in patients who were transferred on both the 3rd and 5th days. Conclusions: Although sperm selection using by sperm chip technique provides advantage in terms of blastocyst quality, use of this technique does not enhance success in terms of clinical pregnancy. Clinical Trial Registration: Approval was obtained from ClinicalTrials.gov with NCT03355937 approval number.

Automated sample-to-answer system for rapid and accurate diagnosis of emerging infectious diseases

Automated sample-to-answer systems that promptly diagnose emerging infectious diseases, such as zoonotic diseases, are crucial to preventing the spread of infectious diseases and future global pandemics. However, automated, rapid, and sensitive diagnostic testing without professionals and sample capacity and type limitations remains unmet needs. Here, we developed an automated sample-to-answer diagnostic system for rapid and accurate detection of emerging infectious diseases from clinical specimens. This integrated system consists of a microfluidic platform for sample preparation and a bio-optical sensor for nucleic acid (NA) amplification/detection. The microfluidic platform concentrates pathogens and NAs in a large sample volume using adipic acid dihydrazide and a low-cost disposable chip. The bio-optical sensor allows label-free, isothermal one-step NA amplification/detection using a ball-lensed optical fiber-based silicon micro-ring resonator sensor. The system is integrated with software to automate testing and perform analysis rapidly and simply; it can distinguish infection status within 80 min. The detection limit of the system (0.96 × 101 PFU) is 10 times more sensitive than conventional methods (0.96 × 102 PFU). Furthermore, we validated the clinical utility of this automated system in various clinical specimens from emerging infectious diseases, including 20 plasma samples for Q fever and 13 (11 nasopharyngeal swabs and 2 saliva) samples for COVID-19. The system showed 100% sensitivity and specificity for detecting 33 samples of emerging infectious diseases, such as Q fever, other febrile diseases, COVID-19, human coronavirus OC43, influenza A, and respiratory syncytial virus A. Therefore, we envision that this automated sample-to-answer diagnostic system will show high potential for diagnosing emerging infectious diseases in various clinical applications.

Sensitive detection of African swine fever virus p54 based on in-situ amplification of disposable electrochemical sensor chip

Sensitive detection of African swine fever virus (ASFV) is important to reduce the loss of pig industry. A highly sensitive disposable electrochemical sensor chip for the detection of ASFV p54 was developed by combining in-situ loop-mediated isothermal amplification (LAMP) with electrochemical sensing technology. The disposable electrochemical sensor chip was prepared by screen printed carbon electrode (SPCE) covered with polydimethylsiloxane membrane as micro-electrolytic cell, and the primers designed according to the virus were fixed on the gold nanoparticles (Au NPs) modified SPCE. The target gene was amplified by in-situ LAMP within 42 min, and the deposition of Au NPs can promote the electron transfer, enhance the electrochemical signal of [Fe(CN)6]3-/4- probe and improve the sensitivity. The detection range of the biosensor was 1.0 × 10-12-1.0 × 10-6 g/L, the detection limit was 3.0 × 10-13 g/L (0.48 copies/µL). In addition, the sensor has good results for the detection of real samples and has broad application prospects.

DropLab: an automated magnetic digital microfluidic platform for sample-to-answer point-of-care testing—development and application to quantitative immunodiagnostics

In point-of-care testing (POCT), tests are performed near patients and results are given rapidly for timely clinical decisions. Immunodiagnostic assays are one of the most important analyses for detecting and quantifying protein-based biomarkers. However, existing POCT immunodiagnostics mainly rely on the lateral flow assay (LFA), which has limited sensitivity or quantification capability. Although other immunodiagnostic assays, such as enzyme-linked immunosorbent assays (ELISAs), offer more sensitive and quantitative results, they require complex liquid manipulations that are difficult to implement in POCT settings by conventional means. Here, we show the development of DropLab, an automated sample-in-answer-out POCT immunodiagnostic platform based on magnetic digital microfluidic (MDM) technology. DropLab performs microbead-based ELISA in droplets to offer more sensitive and quantitative testing results. The intricate liquid manipulations required for ELISA are accomplished by controlling droplets with magnetic microbeads using MDM technology, which enables us to achieve full automation and easy operations with DropLab. Four ELISAs (the sample in triplicates and a negative control) can be run in parallel on the thermoformed disposable chip, which greatly improves the throughput and accuracy compared to those of other POCT immunodiagnostic devices. DropLab was validated by measuring two protein targets and one antibody target. The testing results showed that the limit of detection (LOD) of DropLab matched that of the conventional ELISA in a microwell plate. DropLab brings MDM one step closer to being a viable medical technology that is ready for real-world POCT applications.

Selective determination of nitrite in water and food samples using zirconium oxide (ZrO2)@MWCNTs modified screen printed electrode.

Nitrite ions are being used in different forms as food preservatives acting as flavor enhancers or coloring agents for food products. However, continuous ingestion of nitrite may have severe health implications due to its mutagenic and carcinogenic effects. Thus, this study constructed an electrochemical assay using disposable nano-sensor chip ZrO2@MWCNTs screen printed electrodes (SPE) for the rapid, selective, and sensitive determination of nitrite in food and water samples. As a sensing platform, the use of nanomaterials, including metal oxide nanostructures and carbon nanotubes, exhibited a superior electrocatalytic activity and conductivity. Morphological, structural, and electrochemical analyses were performed using electron microscopy (SEM and TEM), Fourier-transform infrared (FTIR) spectroscopy, electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and chronoamperometry (CA). Accordingly, a wide dynamic linear range (5.0 μM to 100 μM) was obtained with a limit of detection of 0.94 μM by the chronoamperometric technique. In addition, the sensor's selectivity was tested when several non-target species were exposed to the sensor chips while no obvious electrochemical signals were generated when the nitrite ions were not present. Eventually, real food and water sample analysis was conducted, and a high recovery was achieved.

A Rapid Label-Free Disposable Electrochemical Salivary Point-of-Care Sensor for SARS-CoV-2 Detection and Quantification.

The coronavirus disease 2019 (COVID-19) pandemic has created an urgent need for accurate early diagnosis and monitoring. A label-free rapid electrochemical point-of-care (POC) biosensor for SARS-CoV-2 detection in human saliva is reported here to help address the shortcomings of traditional nucleic acid amplification methods and give a quantitative assessment of the viral load to track infection status anywhere, using disposable electrochemical sensor chips. A new chemical construct of gold nanoparticles (GNp) and thionine (Th) are immobilized on carboxylic acid functionalized carbon nanotubes (SWCNT-COOH) for high-performance biosensing. The sensor uses saliva with a one-step pretreatment and simple testing procedure as an analytical medium due to the user-friendly and non-invasive nature of its procurement from patients. The sensor has a response time of 5 min with a limit of detection (LOD) reaching 200 and 500 pM for the freely suspended spike (S) protein in phosphate buffer saline (PBS) and human saliva, respectively. The sensor's performance was also proven for detecting a COVID-19 pseudovirus in an electrolyte solution with a LOD of 106 copies/mL. The results demonstrate that the optimized POC sensor developed in this work is a promising device for the label-free electrochemical biosensing detection of SARS-CoV-2 and different species of viruses.

A Smartphone-Based Disposable Hemoglobin Sensor Based on Colorimetric Analysis.

Hemoglobin is a biomarker of interest for the diagnosis and prognosis of various diseases such as anemia, sickle cell disease, and thalassemia. In this paper, we present a disposable device that has the potential of being used in a setting for accurately quantifying hemoglobin levels in whole blood based on colorimetric analysis using a smartphone camera. Our biosensor employs a disposable microfluidic chip which is made using medical-grade tapes and filter paper on a glass slide in conjunction with a custom-made PolyDimethylSiloaxane (PDMS) micropump for enhancing capillary flow. Once the blood flows through the device, the glass slide is imaged using a smartphone equipped with a custom 3D printed attachment. The attachment has a Light Emitting Diode (LED) that functions as an independent light source to reduce the noise caused by background illumination and external light sources. We then use the RGB values obtained from the image to quantify the hemoglobin levels. We demonstrated the capability of our device for quantifying hemoglobin in Bovine Hemoglobin Powder, Frozen Beef Blood, and human blood. We present a logarithmic model that specifies the relationship between the Red channel of the RGB values and Hemoglobin concentration.

From Lab-on-chip to Lab-in-App: Challenges towards silicon photonic biosensors product developments

This work presents and evaluates different approaches of integrated optical sensors based on photonic integrated circuit (PIC) technologies for refractive index sensing. Bottlenecks in the fabrication flow towards an applicable system are discussed that hinder a cost-effective mass-production for disposable sensor chips. As sensor device, a waveguide coupled micro-ring based approach is chosen which is manufactured in an 8” wafer level process. We will show that the co-integration with a reproducible, scalable and low-cost microfluidic interface is the main challenge which needs to be overcome for future application of silicon technology based PIC sensor chips.

(Digital Presentation) A Disposable Chip Sensor for the Detection of Vancomycin: Studying the Long-Term Stability

Vancomycin is one of the most important anti-bacterial drugs for the treatment of MRSA infection. Continuous monitoring is commonly recommended as it has a low therapeutic window, which is often limited by the equipment cost, and the technical skills required for modern TDM techniques such as HP-LCs and immunoassays. As a result, a cost-effective and quick detection solution for Vancomycin TDM is critical. We have already reported a successful vancomycin sensor on a ceramic base, a paper base, and a PET (polyethylene terephthalate) base, in our previous works 1,2. However, the long-term stability of the sensor for the clinical trial is very important. Therefore, this study focused on the improvement of the stability of the sensor.The PET chip is composed of a PET base on which the silver wiring was printed using an inkjet printer. It contains two holes for electrodes with a 2.0 mm diameter for the counter electrode and a 1.0 mm diameter for the working electrode. The chip also comprises a circular reservoir of diameter 8 mm. VCM imprinted poly(methylene bisacrylamide-co-methacrylic acid-co-Allylaminocarboxypropyonic-3-ferrocene) was grafted on graphite particle surface by a procedure similar to our previous work. This grafted graphite was mixed with a) silicon oil (MIPsi ), and b) paraffin oil (MIPpff ) to make a paste to use as the sensing material. The viscosity of both the oils was the same. We performed the chronoamperometric analysis with a VCM sample solution (0-60 µgmL-1, in phosphate buffer) filled in the sample reservoir.The chronoamperometric analysis time was 15 seconds for each sample. Current obtained at the 10th second was recorded to obtain the calibration curve. The change in current at 10s demonstrated strong linearity with the VCM concentration in both MIPsi and MIPpff , indicating good linearity with the change in current at 10s. Furthermore, this result was obtained using a "single-use" chip, which implies that each concentration was measured using a separate chip. MIPsi and MIPpff were both sensitive to vancomycin. However, when the sensor was packed and kept for 3 days, the MIPsi sensor lost its sensitivity completely. Sensor with the working electrode made of MIPpff, however, retained their sensitivity. MIPpff was further packed and kept for 10 days to have a deeper insight into the effect of binder oil on the long-term stability of the sensor and the sensor was still found to be sensitive. From the results of this study, it can be concluded that a stable sensor that can sensitively detect vancomycin can be made using paraffin oil as the binder oil. References Aaryashree, A., Takeda, Y., Yoshimi, Y., Hatano, A. & Kida, M. A Disposable Vancomycin Sensor Using Molecularly Imprinted Carbon Paste on a Ceramic Chip. in ECS Meeting s vols MA2020-02 3332–3332 (2020).Aaryashree et al. A “Single-Use” Ceramic-Based Electrochemical Sensor Chip Using Molecularly Imprinted Carbon Paste Electrode. Sensors 20, 5847 (2020).

The Simultaneous Detection of Multiple Antibiotics in Milk and Pork Based on an Antibody Chip Biosensor.

In the modern farming industry, the irrational or illegal use of veterinary drugs leads to residues in animal-derived food, which can seriously threaten human health. Efficient detection of low concentrations of drug residues in animal products in a short time is a key challenge for analytical methods. This study proposes to use an antibody chip biosensor for rapid and automated analysis of cephalosporins, aminoglycosides, and sulfonamide antibiotics in pork and milk. 3D polymer slides were applied for the preparation of antibody chips. Ovalbumin (OVA) or bovine serum albumin (BSA) conjugates of the haptens were immobilized as spots on disposable chips. Monoclonal antibodies (mAbs) against cefalexin, ceftiofur, gentamicin, neomycin, and sulfonamides allowed the simultaneous detection of the respective analytes. Antibody binding was detected by a second antibody labeled with Cy3-generating fluorescence, which was scanned a with chip scanner. The limits of detection (LOD) for all the analytes were far below the respective maximum residue limits (MRLs) and ranged from 0.51 to 4.3 µg/kg. The average recoveries of all the analytes in each sample were in the range of 81.6–113.6%. The intra- and inter-assay CV was less than 12.9% and showed good accuracy and precision for all the antibiotics at the MRL level. The sample pretreatment method is simple, and the results are confirmed to be accurate by LC–MS/MS; therefore, this method is valuable for the quality control of animal-derived food.

Versatile and Low-Cost Fabrication of Modular Lock-and-Key Microfluidics for Integrated Connector Mixer Using a Stereolithography 3D Printing.

We present a low-cost and simple method to fabricate a novel lock-and-key mixer microfluidics using an economic stereolithography (SLA) three-dimensional (3D) printer, which costs less than USD 400 for the investment. The proposed study is promising for a high throughput fabrication module, typically limited by conventional microfluidics fabrications, such as photolithography and polymer-casting methods. We demonstrate the novel modular lock-and-key mixer for the connector and its chamber modules with optimized parameters, such as exposure condition and printing orientation. In addition, the optimization of post-processing was performed to investigate the reliability of the fabricated hollow structures, which are fundamental to creating a fluidic channel or chamber. We found out that by using an inexpensive 3D printer, the fabricated resolution can be pushed down to 850 µm and 550 µm size for squared- and circled-shapes, respectively, by the gradual hollow structure, applying vertical printing orientation. These strategies opened up the possibility of developing straightforward microfluidics platforms that could replace conventional microfluidics mold fabrication methods, such as photolithography and milling, which are costly and time consuming. Considerably cheap commercial resin and its tiny volume employed for a single printing procedure significantly cut down the estimated fabrication cost to less than 50 cents USD/module. The simulation study unravels the prominent properties of the fabricated devices for biological fluid mixers, such as PBS, urine and plasma blood. This study is eminently prospective toward microfluidics application in clinical biosensing, where disposable, low-cost, high-throughput, and reproducible chips are highly required.

Automated high-speed 3D imaging of organoid cultures with multi-scale phenotypic quantification.

Current imaging approaches limit the ability to perform multi-scale characterization of three-dimensional (3D) organotypic cultures (organoids) in large numbers. Here, we present an automated multi-scale 3D imaging platform synergizing high-density organoid cultures with rapid and live 3D single-objective light-sheet imaging. It is composed of disposable microfabricated organoid culture chips, termed JeWells, with embedded optical components and a laser beam-steering unit coupled to a commercial inverted microscope. It permits streamlining organoid culture and high-content 3D imaging on a single user-friendly instrument with minimal manipulations and a throughput of 300 organoids per hour. We demonstrate that the large number of 3D stacks that can be collected via our platform allows training deep learning-based algorithms to quantify morphogenetic organizations of organoids at multi-scales, ranging from the subcellular scale to the whole organoid level. We validated the versatility and robustness of our approach on intestine, hepatic, neuroectoderm organoids and oncospheres.

Bridging the Gap between Digital Assays and Point-of-Care Testing: Automated, Low Cost, and Ultrasensitive Detection of Thyroid Stimulating Hormone.

Medical diagnostics is moving toward disease-related target detection at very low concentrations because of the (1) quest for early-stage diagnosis, at a point where only limited target amounts are present, (2) trend toward minimally invasive sample extraction, yielding samples containing low concentrations of target, and (3) need for straightforward sample collection, usually resulting in limited volume collected. Hence, diagnostic tools allowing ultrasensitive target detection at the point-of-care (POC) are crucial for simplified and timely diagnosis of many illnesses. Therefore, we developed an innovative, fully integrated, semi-automated, and economically viable platform based on (1) digital microfluidics (DMF), enabling automated manipulation and analysis of very low sample volumes and (2) low-cost disposable DMF chips with microwell arrays, fabricated via roll-to-roll processes and allowing digital target counting. Thyroid stimulating hormone detection was chosen as a relevant application to show the potential of the system. The assay buffer was selected using design of experiments, and the assay was optimized in terms of reagent concentration and incubation time toward maximum sensitivity. The hydrophobic-in-hydrophobic microwells showed an unparalleled seeding efficiency of 97.6% ± 0.6%. A calculated LOD of 0.0013 μIU/mL was obtained, showing the great potential of the platform, especially taking into account the very low sample volume analyzed (1.1 μL). Although validation (in biological matrix) and industrialization (full automation) steps still need to be taken, it is clear that the combination of DMF, low-cost DMF chips, and digital analyte counting in microwell arrays enables the implementation of ultrasensitive and reliable target detection at the POC.