A High Spatiotemporal Iontronic Single-Cell Viscometer

A bio-fabricated tesla valves and ultrasound waves-powered blood plasma viscometer

Introduction: There is clinical evidence that the fresh blood viscosity is an important indicator in the development of vascular disorder and coagulation. However, existing clinical viscosity measurement techniques lack the ability to measure blood viscosity and replicate the in-vivo hemodynamics simultaneously. Methods: Here, we fabricate a novel digital device, called Tesla valves and ultrasound waves-powered blood plasma viscometer (TUBPV) which shows capacities in both viscosity measurement and coagulation monitoring. Results: Based on the Hagen-Poiseuille equation, viscosity analysis can be faithfully performed by a video microscopy. Tesla-like channel ensured unidirectional liquid motion with stable pressure driven that was triggered by the interaction of Tesla valve structure and ultrasound waves. In few seconds the TUBPV can generate an accurate viscosity profile on clinic fresh blood samples from the flow time evaluation. Besides, Tesla-inspired microchannels can be used in the real-time coagulation monitoring. Discussion: These results indicate that the TUBVP can serve as a point-of-care device in the ICU to evaluate the blood's viscosity and the anticoagulation treatment.

Insights into Materials, Physics, and Applications in Flexible and Wearable Acoustic Sensing Technology

Sound plays a crucial role in the perception of the world. It allows to communicate, learn, and detect potential dangers, diagnose diseases, and much more. However, traditional acoustic sensors are limited in their form factors, being rigid and cumbersome, which restricts their potential applications. Recently, acoustic sensors have made significant advancements, transitioning from rudimentary forms to wearable devices and smart everyday clothing that can conform to soft, curved, and deformable surfaces or surroundings. In this review, the latest scientific and technological breakthroughs with insightful analysis in materials, physics, design principles, fabrication strategies, functions, and applications of flexible and wearable acoustic sensing technology are comprehensively explored. The new generation of acoustic sensors that can recognize voice, interact with machines, control robots, enable marine positioning and localization, monitor structural health, diagnose human vital signs in deep tissues, and perform organ imaging is highlighted. These innovations offer unique solutions to significant challenges in fields such as healthcare, biomedicine, wearables, robotics, and metaverse. Finally, the existing challenges and future opportunities in the field are addressed, providing strategies to advance acoustic sensing technologies for intriguing real-world applications and inspire new research directions.

A hollow Ag/AgCl nanoelectrode for single-cell chloride detection

This work reports the construction of a miniaturized Ag/AgCl nanoelectrode on a nanopipette, which is capable of dual-functions of single-cell drug infusion and chloride detection and is envisioned to promote the study of chloride-correlated therapeutic effects.

θ-Nanopore Ratiometry

Developing nanoscale ratiometric techniques capable of biochemical response should prove of significance for precise applications with stringent spatial and biological restrictions. Here we present and devise the concept of θ-nanopore ratiometry, which uses ratiometric signals that could well address the serious concerns about device deviation in fabrication and nonspecific adsorption in the detection. As exemplified by a 200 nm θ-nanopore toward miRNA detection, the ±20 nm aperture drift could be mitigated and the issue of nonspecific adsorption could be minimized in the complex cytosolic environment. Practical application of this θ-nanopore ratiometry realizes the measurements of cytosolic miRNA-10b. This work has not only established a nanoscopic ratiometric technique but also enriched the extant armory of nanotools for single-cell studies and beyond.

An Ultrasensitive and Efficient microRNA Nanosensor Empowered by the CRISPR/Cas Confined in a Nanopore

This work presents a clustered regularly interspaced short palindromic repeat (CRISPR)/Cas-nanopipette nano-electrochemistry (Cas = CRISPR-associated proteins) capable of ultrasensitive microRNA detection. Nanoconfinement of the CRISPR/Cas13a within a nanopipette leads to a high catalytic efficacy of ca. 169 times higher than that in bulk electrolyte, contributing to the amplified electrochemical responses. CRISPR/Cas13a-enabled detection of representative microRNA-25 achieves a low limit of detection down to 10 aM. Practical application of this method is further demonstrated for single-cell and real human serum detection. Its general applicability is validated by addressing microRNA-141 and the SARS-CoV-2 RNA gene fragment. This work introduces a new CRISPR/Cas-empowered nanotechnology for ultrasensitive nano-electrochemistry and bioanalysis.

Alkaline Phosphatase-Mediated Bioetching of CoOOH/BiVO4 for Signal-On Organic Photoelectrochemical Transistor Bioanalysis

Organic photoelectrochemical transistor (OPECT) bioanalytics has recently appeared as a promising route for biological measurements, which has major implications in both next-generation photoelectrochemical (PEC) bioanalysis and futuristic biorelated implementations. Via biological dissociation of materials, bioetching is a useful technique for bio-manufacturing and bioanalysis. The intersection of these two domains is expected to be a possible way to achieve innovative OPECT bioanalytics. Herein, we validate such a possibility, which is exemplified by alkaline phosphatase (ALP)-mediated bioetching of a CoOOH/BiVO₄ gate for a signal-on OPECT immunoassay of human immunoglobulin G (HIgG) as the model target. Specifically, target-dependent bioetching of the upper CoOOH layer could result into an enhanced electrolyte contact and light accessibility to BiVO₄, leading to the modulated response of the polymeric poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) channel that could be monitored by the channel current. The introduced biosensor achieves sensitive detection of HIgG with high selectivity and sensitivity. This work features bioetching-enabled high-efficacy OPECT bioanalysis and is anticipated to serve as a generic protocol, considering the diverse bioetching routes.