Near-Field Electrochemistry Enables a Wearable Sensor-Embedded Smart Facemask for Personalized Respiratory Assessment.

Continuous monitoring of respiratory waveforms with daily wearable devices can provide valuable physiological data for health assessments. However, developing miniature sensors that feature both high portability and stability for real-time monitoring of respiratory waveforms remains a challenge. We recently developed a near-field electrochemical mechanism that could be used as an emerging sensing strategy for respiratory monitoring in anesthetic rats.

Tailoring the Electrocatalytic Properties of Porphyrin Covalent Organic Frameworks for Highly Selective Oxygen Sensing .

selective sensing of oxygen (O) dynamics in the central nervous system could provide insights into energy metabolism and neural activities. Although the electrocatalytic four-electron oxygen reduction reaction (ORR) paves an effective way to the electrochemical sensing of O , the concurrent hydrogen peroxide reduction reaction (HPRR) within the potential windows for four-electron ORR unfortunately poses a great challenge to the conventional mechanism employed for selective electrochemical O sensing. In this work, we find that regulation of the linkers within the skeleton of porphyrin-based covalent organic frameworks (COFs) could improve the selectivity of the O sensor against hydrogen peroxide (HO).

Electrolyte-Gated Ionic Transistor for Highly Sensitive and Selective Iontronic Sensing.

Iontronic sensors based on confined space have garnered significant attention due to their promising applications, ranging from single-cell analysis to studies. However, their limited sensitivity has constrained their effectiveness in studying molecular information during physiological and pathological processes. Here, we demonstrate an electrolyte-gated ionic transistor (EGIT) by integrating the confined ion transport behavior in a double-barreled micropipet with an electrolyte-gated transistor configuration, achieving highly sensitive and selective sensing.

Single-Vesicle Electrochemistry in Fresh Brain Slices Enables In Situ Quantification of Vesicular Monoamine.

The quantitative analysis of vesicular neurotransmitters in neurons in situ is paramount for investigating neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease (PD). Unfortunately, a direct approach for monitoring neurotransmitter chemistry in single vesicles in fresh brain tissue has remained inaccessible so far. Here, we introduce an innovative platform of single-vesicle electrochemistry (SVE) in fresh brain tissue, enabling the quantification of neurotransmitters at the single-vesicle level for both soma and varicosity.

Optically Modulated Nanofluidic Ionic Transistor for Neuromorphic Functions.

Neuromorphic systems that can emulate the behavior of neurons have garnered increasing interest across interdisciplinary fields due to their potential applications in neuromorphic computing, artificial intelligence and brain-machine interfaces. However, the optical modulation of nanofluidic ion transport for neuromorphic functions has been scarcely reported. Herein, inspired by biological systems that rely on ions as signal carriers for information perception and processing, we present a nanofluidic transistor based on a metal-organic framework membrane (MOFM) with optically modulated ion transport properties, which can mimic the functions of biological synapses.

Inflammation-free electrochemical in vivo sensing of dopamine with atomic-level engineered antioxidative single-atom catalyst.

Electrochemical methods with tissue-implantable microelectrodes provide an excellent platform for real-time monitoring the neurochemical dynamics in vivo due to their superior spatiotemporal resolution and high selectivity and sensitivity. Nevertheless, electrode implantation inevitably damages the brain tissue, upregulates reactive oxygen species level, and triggers neuroinflammatory response, resulting in unreliable quantification of neurochemical events. Herein, we report a multifunctional sensing platform for inflammation-free in vivo analysis with atomic-level engineered Fe single-atom catalyst that functions as both single-atom nanozyme with antioxidative activity and electrode material for dopamine oxidation.

Confining Thiolysis of Dinitrophenyl Ether to a Luminescent Metal-Organic Framework with a Large Stokes Shift for Highly Efficient Detection of Hydrogen Sulfide in Rat Brain.

Hydrogen sulfide (HS) is a gaseous signaling molecule that regulates various physiological and pathological processes in the central nervous system. It is vital to develop an effective method to detect HS in vivo to elucidate its critical role. However, current fluorescent probes for accurate quantification of HS still face big challenges due to complicated fabrication, small Stokes shift, unsatisfactory selectivity, and especially delayed response time.

Atom-pair engineering of single-atom nanozyme for boosting peroxidase-like activity.

Constructing atom-pair engineering and improving the activity of metal single-atom nanozyme (SAzyme) is significant but challenging. Herein, we design the atom-pair engineering of Zn-SA/CNCl SAzyme by simultaneously constructing Zn-N sites as catalytic sites and Zn-NCl sites as catalytic regulator. The Zn-NCl catalytic regulators effectively boost the peroxidase-like activities of Zn-N catalytic sites, resulting in a 346-fold, 1496-fold, and 133-fold increase in the maximal reaction velocity, the catalytic constant and the catalytic efficiency, compared to Zn-SA/CN SAzyme without the Zn-NCl catalytic regulator.

Transmembrane Graphene as an Electron Tunnel to Regulate the Intracellular Redox State.

Cellular redox homeostasis is essential for maintaining cellular activities, such as DNA synthesis and gene expression. Inspired by this, new therapeutic interventions have been rapidly developed to modulate the intracellular redox state using artificial transmembrane electron transport. However, current approaches that rely on external electric field polarization can disrupt cellular functions, limiting their application.

General In Situ Engineering of Carbon-Based Materials on Carbon Fiber for In Vivo Neurochemical Sensing.

Developing real-time, dynamic, and in situ analytical methods with high spatial and temporal resolutions is crucial for exploring biochemical processes in the brain. Although in vivo electrochemical methods based on carbon fiber (CF) microelectrodes are effective in monitoring neurochemical dynamics during physiological and pathological processes, complex post modification hinders large-scale productions and widespread neuroscience applications. Herein, we develop a general strategy for the in situ engineering of carbon-based materials to mass-produce functional CFs by introducing polydopamine to anchor zeolitic imidazolate frameworks as precursors, followed by one-step pyrolysis.

Vitamin C Drives Reentrant Actin Phase Transition: Biphasic Exocytosis Regulation Revealed by Single-Vesicle Electrochemistry.

Unveiling molecular mechanisms that dominate protein phase dynamics has been a pressing need for deciphering the intricate intracellular modulation machinery. While ions and biomacromolecules have been widely recognized for modulating protein phase separations, effects of small molecules that essentially constitute the cytosolic chemical atmosphere on the protein phase behaviors are rarely understood. Herein, we report that vitamin C (V), a key small molecule for maintaining a reductive intracellular atmosphere, drives reentrant phase transitions of myosin II/F-actin (actomyosin) cytoskeletons.

Graphdiyne as a Highly Efficient and Neuron-Targeted Photothermal Transducer for Neuromodulation.

Photothermal modulation of neural activity offers a promising approach for understanding brain circuits and developing therapies for neurological disorders. However, the low neuron selectivity and inefficient light-to-heat conversion of existing photothermal nanomaterials significantly limit their potential for neuromodulation. Here, we report that graphdiyne (GDY) can be developed into an efficient neuron-targeted photothermal transducer for modulation of neuronal activity through rational surface functionalization.

An octopamine-specific GRAB sensor reveals a monoamine relay circuitry that boosts aversive learning.

Octopamine (OA), analogous to norepinephrine in vertebrates, is an essential monoamine neurotransmitter in invertebrates that plays a significant role in various biological functions, including olfactory associative learning. However, the spatial and temporal dynamics of OA remain poorly understood due to limitations associated with the currently available methods used to detect it. To overcome these limitations, we developed a genetically encoded GPCR  activation-based (GRAB) OA sensor called GRAB.

Aptamer-Based Potentiometric Sensor Enables Highly Selective and Neurocompatible Neurochemical Sensing in Rat Brain.

Selective and nondisruptive in vivo neurochemical monitoring within the central nervous system has long been a challenging endeavor. We introduce a new sensing approach that integrates neurocompatible galvanic redox potentiometry (GRP) with customizable phosphorothioate aptamers to specifically probe dopamine (DA) dynamics in live rat brains. The aptamer-functionalized GRP (aptGRP) sensor demonstrates nanomolar sensitivity and over a 10-fold selectivity for DA, even amidst physiological levels of major interfering species.

Highly Sensitive Near-Field Electrochemical Sensor for In Vivo Monitoring of Respiratory Patterns.

Real-time tracking of respiratory patterns provides noninvasive and quick access for evaluating pathophysiological conditions yet remains challenging due to limited temporal resolution and poor sensitivity to dig out fingerprints of respiratory waveforms. Here, we report an electrochemical sensor for accurately tracing respiratory patterns of small animal models based on the electrochemical impedance mechanism for wireless coupling of a graphdiyne oxide (GYDO)-modified sensing coil chip and a reader coil chip via near-field magnetic induction. In the electrochemical impedance measurement mode, an alternating current is applied through the reader coil chip to perturb proton transport at the GYDO interface of the sensing coil chip.

An octopamine-specific GRAB sensor reveals a monoamine relay circuitry that boosts aversive learning.

Octopamine (OA), analogous to norepinephrine in vertebrates, is an essential monoamine neurotransmitter in invertebrates that plays a significant role in various biological functions, including olfactory associative learning. However, the spatial and temporal dynamics of OA remain poorly understood due to limitations associated with the currently available methods used to detect it. To overcome these limitations, we developed a genetically encoded GPCR activation-based (GRAB) OA sensor called GRAB.

Enzymatic Galvanic Redox Potentiometry for In Vivo Biosensing.

Redox potentiometry has emerged as a new platform for in vivo sensing, with improved neuronal compatibility and strong tolerance against sensitivity variation caused by protein fouling. Although enzymes show great possibilities in the fabrication of selective redox potentiometry, the fabrication of an enzyme electrode to output open-circuit voltage () with fast response remains challenging. Herein, we report a concept of novel enzymatic galvanic redox potentiometry (GRP) with improved time response coupling the merits of the high selectivity of enzyme electrodes with the excellent biocompatibility and reliability of GRP sensors.

Electroless Deposition of Palladium Nanoparticles on Graphdiyne Boosts Electrochemiluminescence.

Modulating the electronic structure of metal nanoparticles via metal-support interaction has attracted intense interest in the field of catalytic science. However, the roles of supporting substrates in regulating the catalytic properties of electrochemiluminescence (ECL) remain elusive. Here, we find that the use of graphdiyne (GDY) as the substrate for electroless deposition of Pd nanoparticles (Pd/GDY) produces the most pronounced anodic signal enhancement in luminol-dissolved oxygen (O) ECL system as co-reactant accelerator over other carbon-based Pd composite nanomaterials.

Ion-Selective Micropipette Sensor for In Vivo Monitoring of Sodium Ion with Crown Ether-Encapsulated Metal-Organic Framework Subnanopores.

In vivo sensing of the dynamics of ions with high selectivity is essential for gaining molecular insights into numerous physiological and pathological processes. In this work, we report an ion-selective micropipette sensor (ISMS) through the integration of functional crown ether-encapsulated metal-organic frameworks (MOFs) synthesized in situ within the micropipette tip. The ISMS features distinctive sodium ion (Na) conduction and high selectivity toward Na sensing.

A Potentiometric Dual-Channel Microsensor Reveals that Fluctuation of H S is Less pH-Dependent During Spreading Depolarization in the Rat Brain.

Spreading depolarization (SD) is one of the most common neuropathologic phenomena in the nervous system, relating to numerous diseases. However, real-time monitoring the rapid chemical changes during SD to probe the molecular mechanism remains a great challenge. We develop a potentiometric dual-channel microsensor for simultaneous monitoring of H S and pH featuring excellent selectivity and spatiotemporal resolution.

High-Performance Electrochemical Actuator under an Ultralow Driving Voltage with a Mixed Electronic-Ionic Conductive Metal-Organic Framework.

Although versatile deformation, high flexibility, and environmental friendliness of electrochemical actuators (EAs) have made them promising in bioinspired soft robots and biomedical devices, the relatively high driving voltages unfortunately impose great restrictions on their applications in low-energy and human-friendly electronics. Here, we find that the uses of a mixed electronic-ionic conductive metal-organic framework (c-MOF), i.e.

Direct Quantification of Nanoplastics Neurotoxicity by Single-Vesicle Electrochemistry.

Nanoplastics are recently recognized as neurotoxic factors for the nervous systems. However, whether and how they affect vesicle chemistry (i.e.