Detection and monitoring of lactate and glucose levels in biological fluids and cell cultures are essential for understanding metabolic disorders. While electrochemical biosensors are commonly used, traditional enzymatic sensors face challenges related to stability, reproducibility, and cost. To address these limitations, we developed non-enzymatic sensors for lactate and glucose detection using nanostructured nickel oxide (NiO)–modified screen-printed carbon electrodes. The sensors were fabricated by drop-casting a NiO/Nafion/ethanol dispersion onto the working electrode, and their performance was evaluated using cyclic voltammetry and amperometry. Optimal sensitivity and linearity were achieved at a working potential of ∼0.5 V. The sensors exhibited linear responses for both lactate and glucose in the 0.1–5 mM range, with detection limits of 0.03 mM (lactate) and 0.025 mM (glucose), and sensitivities of 1.564 μA/mM (lactate) and 1.842 μA/mM (glucose) in 0.1 M NaOH–KCl electrolyte. To address glucose interference in lactate sensing, dual-sensing strategies were employed by varying Nafion concentration, applying differential potentials, or modifying the sensors with Prussian Blue to achieve selective detection. Validation against commercial lactate and glucose assay kits in cell culture medium showed good agreement, confirming the sensors’ accuracy. Finally, the sensor was integrated with a microfluidic chip, demonstrating its potential as a flow-through, enzyme-free metabolic sensor for future organ-on-a-chip applications.

To enhance the detection and analysis of µm-size biological particles (like extracellular vesicles and exosomes) essential in the diagnosis of many diseases like sepsis and cancer, we developed a Flow-Cytometer-in-a-Fiber device that was able to reliably detect 1 µm fluorescent polystyrene beads. This technology allows a fast detection and identification of the different particles, paving the way for an advanced point-of-care diagnostic platform that could be used, for example, in cancer diagnostics. Furthermore, the small footprint of this device allows an easy integration with other existing diagnostic platforms.

Neurons depend on glucose to sustain their high energetic demands; yet, ketone bodies can serve as alternative substrates during ketogenic states. Here, we examined how β-hydroxybutyrate reshapes metabolism and function in human iPSC-derived neurons. Neurons generated from neuroepithelial stem cells were cultured in glucose-rich media or low-glucose media supplemented with β-hydroxybutyrate. We developed an electrochemical biosensor for ketone detection and validated its performance by cyclic voltammetry and amperometry, achieving linear sensitivity in the 0.01 to 0.1 mM range. Metabolic changes for neurons were assessed through glucose consumption and lactate production, and transcriptional profiling revealed reduced expression of selected metabolic and ketone-associated genes under ketone supplementation. Calcium imaging further showed lower firing rates in ketone exposed neurons compared with glucose conditions. Together, these results demonstrate how alternative energy substrates modulate neuronal metabolism and excitability, providing a framework to evaluate metabolic interventions for neurological disorders.

Rolling circle amplification (RCA) combined with padlock probes presents a promising tool for direct detection and genotyping of viral RNA, offering advantages over conventional methods like RT-PCR. This isothermal process enables highly sensitive and specific amplification of nucleic acids without the need for thermal cycling, making it suitable for point-of-care applications. In this study, we demonstrate a microfluidic and RCA-based method for the direct detection of SARS-CoV-2 RNA and variant profiling, bypassing the reverse transcription step. Our approach allows for the identification of single nucleotide polymorphisms (SNPs) specific to viral variants, enhancing the detection sensitivity through the circle-to-circle amplification (C2CA) technique. This methodology shows potential as a robust, cost-effective platform for viral diagnostics, capable of being fully automated and integrated with miniaturized detection systems for efficient use in both resource-rich and resource-limited settings.

Elasto-inertial microfluidics enables precise particle focusing and separation, but most experimental studies rely on fluorescence microscopy, which provides only 2D information and cannot resolve out-of-plane motion. Here, we combine fluorescence imaging with Optical Coherence Tomography (OCT) to obtain complementary lateral and depth-resolved (resolution along the beam: 2.58 μm in the present medium) particle distributions in microfluidic channels. Using 3 μm and 5 μm particles in a PEO solution at flow rates of 1–50 μL/min, fluorescence microscope captures lateral focusing followed by lateral defocusing with the increasing flow rate, while OCT reveals the vertical distribution of particles at the focusing and defocusing states. These results demonstrate that OCT is a promising method to obtain essential 3D information in elasto-inertial flows that complements fluorescence microscopy and enables a more complete understanding of particle behavior in elasto-inertial flows.

A lab-in-a-fiber component was fabricated using an optical fiber and a fiber capillary. It was used in a test suspension of fluorescently labeled and unlabeled cells and enabled detection of the labeled cells. Subsequently the labeled cells were selectively collected via suction into the capillary. A novel sampling technique reduced photobleaching of the labeled cells, extending the measurement time. The collected cells remained viable for downstream analysis. This platform’s low fabrication cost, simplicity, compatibility with standard laboratory equipment, and capacity for fully automated cell capture highlights its potential for future applications in minimally invasive sample collection and point-of-care diagnostics. We demonstrate this LiF device to showcase the capability of optical fiber technology in creating low-cost, low-complexity cancer diagnostic devices. Furthermore, the LiF device holds promise for in vivo diagnostics, facilitating cell isolation and analysis.

The advancement of biopharmaceutical manufacturing, particularly continuous processing, has heightened the need for next-generation analytical tools approaching real-time monitoring of critical quality attributes (CQAs) and process parameters (CPPs). Current methods, primarily offline and labor-intensive, fail at delivering analytical information that can be used for process analytical technology (PAT) to control and optimize the manufacturing process, while also lacking the ability of multi-attribute monitoring, thus requiring a large number of samples (or sampling amount) to be collected. This work introduces the concept of PAT-on-a-chip, consisting of an integrated microfluidic platform designed to perform at-line analysis and characterization of cell culture samples in the context of monoclonal antibody (mAb) production. Specifically, a sample preparation-free miniaturized lectin-based assay was developed to measure levels of high mannose glycans and integrated with affinity-based assays to measure mAb titers and key impurities, namely Chinese hamster ovary (CHO) host cell proteins (HCP), within the same chip, resorting to a common colorimetric readout. The microfluidic chips were operated in a customized and integrated instrument comprising miniaturized photodiodes, connected to a graphical user interface for data recording and signal quantification. The PAT-on-a-chip unit allowed to achieve fit-for-purpose analyte quantification, while offering performance comparable to state-of-the-art offline analytical methods (Pearson R > 0.93), namely capillary electrophoresis with laser-induced fluorescence (CE-LIF) for glycan analysis, well plate immunoassays for CHO HCP and protein A HPLC for mAb titers, thus validating its potential to expand the modern PAT toolbox.

Nanoscale biological particles, such as lipoproteins (10–80 nm) or extracellular vesicles (30–200 nm), play pivotal roles in health and disease, including conditions like cardiovascular disorders and cancer. Their effective analysis is crucial for applications in diagnostics, quality control, and nanomedicine development. While elasto-inertial focusing offers a powerful method to manipulate particles without external fields, achieving consistent focusing of nanoparticles (<500 nm) has remained a challenge. In this study, elasto-inertial focusing of nanoparticles as small as 25 nm is experimentally demonstrated using straight high-aspect-ratio microchannels in a sheathless flow. Systematic investigations reveal the influence of channel width, particle size, viscoelastic concentration, and flow rate on focusing behavior. Additionally, through numerical simulations and experimental validation, insights are provided into particle migration dynamics and viscoelastic forces governing nanoparticle focusing. Finally, biological particles, including liposomes (90–140 nm), extracellular vesicles (100 nm), and lipoproteins (10–25 nm) is successfully focused, under optimized conditions, showcasing potential applications in medical diagnostics and targeted drug delivery. These findings mark a significant advancement toward size-based high-resolution particle separation, with implications for biomedicine and environmental sciences.

Laboratory automation effectively increases the throughput in sample analysis, reduces human errors in sample processing, as well as simplifies and accelerates the overall logistics. Automating diagnostic testing workflows in peripheral laboratories and also in near-patient settings -like hospitals, clinics and epidemic control checkpoints- is advantageous for the simultaneous processing of multiple samples to provide rapid results to patients, minimize the possibility of contamination or error during sample handling or transport, and increase efficiency. However, most automation platforms are expensive and are not easily adaptable to new protocols. Here, we address the need for a versatile, easy-to-use, rapid and reliable diagnostic testing workflow by combining open-source modular automation (Opentrons) and automation-compatible molecular biology protocols, easily adaptable to a workflow for infectious diseases diagnosis by detection on paper-based diagnostics. We demonstrated the feasibility of automation of the method with a low-cost Neisseria meningitidis diagnostic test that utilizes magnetic beads for pathogen DNA isolation, isothermal amplification, and detection on a paper-based microarray. In summary, we integrated open-source modular automation with adaptable molecular biology protocols, which was also faster and cheaper to perform in an automated than in a manual way. This enables a versatile diagnostic workflow for infectious diseases and we demonstrated this through a low-cost N. meningitidis test on paper-based microarrays.

The health hazards of micro- and nanoplastic contaminants in drinking water has recently emerged as an area of concern to policy makers and industry. Plastic contaminants range in size from micro- (5 mm to 1 μm) to nanoplastics (<1 μm). Microfluidics provides many tools for particle manipulation at the microscale, particularly in diagnostics and biomedicine, but has in general a limited capacity to process large volumes. Drinking water and environmental samples with low-level contamination of microplastics require processing of deciliter to liter sample volumes to achieve statistically relevant particle counts. Here, we introduce the EchoGrid, an acoustofluidics device for high throughput continuous flow particle enrichment into a robust array of particle clusters. The EchoGrid takes advantage of highly efficient particle capture through the integration of a micropatterned transducer for surface displacement-based acoustic trapping in a glass and polymer microchannel. Silica seed particles were used as anchor particles to improve capture performance at low particle concentrations and high flow rates. The device was able to maintain the silica grids at a flow rate of 50 mL/min. In terms of enrichment, the device is able to double the final pellet’s microplastic concentration every 78 s for 23 μm particles and every 51 s for 10 μm particles at a flow rate of 5 mL/min. In conclusion, we demonstrate the usefulness of the EchoGrid by capturing microplastics in challenging conditions, such as large sample volumes with low microparticle concentrations, without sacrificing the potential of integration with downstream analysis for environmental monitoring.