Enzyme-Mediated Organic Neurohybrid Synapses.

The development of organic artificial synapses that exhibit biomimicry features also may enable a more seamless integration of neuroelectronic devices in the nervous system, allowing artificial neuromodulation to be perceived as natural behavior by neuronal cells. Nevertheless, the capability to interact with both electroactive and non-electroactive neurotransmitters remains a challenge since state-of-the-art devices mainly rely on the oxidation of electroactive species. Here, the study proposes an organic artificial synapse engineered to enable interaction with non-electroactive species present in the central nervous system.

Development and Calibration of a Microfluidic, Chip-Based Sensor System for Monitoring the Physical Properties of Water Samples in Aquacultures.

In this work, we present a compact, bifunctional chip-based sensor setup that measures the temperature and electrical conductivity of water samples, including specimens from rivers and channels, aquaculture, and the Atlantic Ocean. For conductivity measurements, we utilize the impedance amplitude recorded via interdigitated electrode structures at a single triggering frequency. The results are well in line with data obtained using a calibrated reference instrument.

Template bacteria-free fabrication of surface imprinted polymer-based biosensor for E. coli detection using photolithographic mimics: Hacking bacterial adhesion.

As one class of molecular imprinted polymers (MIPs), surface imprinted polymer (SIP)-based biosensors show great potential in direct whole-bacteria detection. Micro-contact imprinting, that involves stamping the template bacteria immobilized on a substrate into a pre-polymerized polymer matrix, is the most straightforward and prominent method to obtain SIP-based biosensors. However, the major drawbacks of the method arise from the requirement for fresh template bacteria and often non-reproducible bacteria distribution on the stamp substrate.

A modular organic neuromorphic spiking circuit for retina-inspired sensory coding and neurotransmitter-mediated neural pathways.

Signal communication mechanisms within the human body rely on the transmission and modulation of action potentials. Replicating the interdependent functions of receptors, neurons and synapses with organic artificial neurons and biohybrid synapses is an essential first step towards merging neuromorphic circuits and biological systems, crucial for computing at the biological interface. However, most organic neuromorphic systems are based on simple circuits which exhibit limited adaptability to both external and internal biological cues, and are restricted to emulate only specific the functions of an individual neuron/synapse.

Actively Driven Light-Addressable Sensor/Actuator System for Automated pH Control for the Integration in Lab-On-A-Chip (LoC) Platforms.

The miniaturization of microfluidic systems usually comes at the cost of more difficult integration of sensors and actuators inside the channel. As an alternative, this work demonstrates the embedding of semiconductor-based sensor and actuator technologies that can be spatially and temporally controlled from outside the channel using light. The first element is a light-addressable potentiometric sensor, consisting of an Al/Si/SiO/SiN structure, that can measure pH changes at the SiN/electrolyte interface.

PVDF/poly(3-methylthiophene)/MWCNT nanocomposites for EMI shielding in the microwave range.

This work presents a new approach to enhance EMI shielding efficiency of nanocomposites of dielectric polymers, multiwalled carbon nanotubes (MWCNTs) and intrinsically conducting polymers for account of using core-shell morphology for conducting components. To realize this approach new ternary nanocomposites of poly(vinylidene fluoride) (PVDF), MWCNTs and poly(3-methylthiophene) doped by Cl anions (P3MT) were prepared through synthesis of thermally stable core/shell nanocomposites PVDF/P3MT and MWCNT/P3MT. These binary nanocomposites were mixed with pure MWCNTs or PVDF followed by compression molding to prepare the ternary nanocomposites of different morphology to discriminate their EMI shielding properties in a wide frequency range (1-67 GHz).

Expressing Optogenetic Actuators Fused to N-terminal Mucin Motifs Delivers Targets to Specific Subcellular Compartments in Polarized Cells.

Optogenetics is a powerful approach in neuroscience research. However, other tissues of the body may benefit from controlled ion currents and neuroscience may benefit from more precise optogenetic expression. The present work constructs three subcellularly-targeted optogenetic actuators based on the channelrhodopsin ChR2-XXL, utilizing 5, 10, or 15 tandem repeats (TR) from mucin as N-terminal targeting motifs and evaluates expression in several polarized and non-polarized cell types.

Azobenzene-based optoelectronic transistors for neurohybrid building blocks.

Exploiting the light-matter interplay to realize advanced light responsive multimodal platforms is an emerging strategy to engineer bioinspired systems such as optoelectronic synaptic devices. However, existing neuroinspired optoelectronic devices rely on complex processing of hybrid materials which often do not exhibit the required features for biological interfacing such as biocompatibility and low Young's modulus. Recently, organic photoelectrochemical transistors (OPECTs) have paved the way towards multimodal devices that can better couple to biological systems benefiting from the characteristics of conjugated polymers.

Facile Purification and Use of Tobamoviral Nanocarriers for Antibody-Mediated Display of a Two-Enzyme System.

Immunosorbent turnip vein clearing virus (TVCV) particles displaying the IgG-binding domains D and E of protein A (PA) on every coat protein (CP) subunit (TVCV) were purified from plants via optimized and new protocols. The latter used polyethylene glycol (PEG) raw precipitates, from which virions were selectively re-solubilized in reverse PEG concentration gradients. This procedure improved the integrity of both TVCV and the wild-type subgroup 3 tobamovirus.

Validation of transparent and flexible neural implants for simultaneous electrophysiology, functional imaging, and optogenetics.

The combination of electrophysiology and neuroimaging methods allows the simultaneous measurement of electrical activity signals with calcium dynamics from single neurons to neuronal networks across distinct brain regions . While traditional electrophysiological techniques are limited by photo-induced artefacts and optical occlusion for neuroimaging, different types of transparent neural implants have been proposed to resolve these issues. However, reproducing proposed solutions is often challenging and it remains unclear which approach offers the best properties for long-term chronic multimodal recordings.

Spontaneous movements and their impact on neural activity fluctuate with latent engagement states.

Existing work demonstrates that animals alternate between engaged and disengaged states during perceptual decision-making. To understand the neural signature of these states, we performed cortex-wide measurements of neural activity in mice making auditory decisions. The trial-averaged magnitude of neural activity was similar in the two states.

Capacitive field-effect biosensor modified with a stacked bilayer of weak polyelectrolyte and plant virus particles as enzyme nanocarriers.

This work presents a new approach for the development of field-effect biosensors based on an electrolyte-insulator-semiconductor capacitor (EISCAP) modified with a stacked bilayer of weak polyelectrolyte and tobacco mosaic virus (TMV) particles as enzyme nanocarriers. With the aim to increase the surface density of virus particles and thus, to achieve a dense immobilization of enzymes, the negatively charged TMV particles were loaded onto the EISCAP surface modified with a positively charged poly(allylamine hydrochloride) (PAH) layer. The PAH/TMV bilayer was prepared on the TaO-gate surface by means of layer-by-layer technique.

Scale-up synthesis of high-quality solid-state-processed CsCuX (X = Cl, Br, I) perovskite nanocrystal materials toward near-ultraviolet flexible electronic properties.

High-quality CsCuX and CsCuX (X = Cl, Br, I) nanocrystals (NCs) exhibit excellent optoelectronic, physical, and chemical properties for detection of UV radiation due to large carrier mobility and lifetime, and heavy atoms. The nanocrystal materials can be prepared a low-cost and simple solid-state synthesis. However, poor reproducibility and complex synthesis methods of obtaining perovskite NC thin films represent a drawback for the fabrication of the commercial photoelectric device.

Determination of Stiffness and the Elastic Modulus of 3D-Printed Micropillars with Atomic Force Microscopy-Force Spectroscopy.

Nowadays, many applications in diverse fields are taking advantage of micropillars such as optics, tribology, biology, and biomedical engineering. Among them, one of the most attractive is three-dimensional microelectrode arrays for in vivo and in vitro studies, such as cellular recording, biosensors, and drug delivery. Depending on the application, the micropillar's optimal mechanical response ranges from soft to stiff.

Pyramidal cell types drive functionally distinct cortical activity patterns during decision-making.

Understanding how cortical circuits generate complex behavior requires investigating the cell types that comprise them. Functional differences across pyramidal neuron (PyN) types have been observed within cortical areas, but it is not known whether these local differences extend throughout the cortex, nor whether additional differences emerge when larger-scale dynamics are considered. We used genetic and retrograde labeling to target pyramidal tract, intratelencephalic and corticostriatal projection neurons and measured their cortex-wide activity.

Intrinsic Multienzyme-like Activities of the Nanoparticles of Mn and Fe Cyano-Bridged Assemblies.

This study investigates the intrinsic multienzyme-like properties of the non-stabilized nanocrystalline nanoparticles of manganese-doped Prussian blue (Mn-PB) nanozymes and Prussian blue (PB) nanozymes in chemical and electrocatalytic transformations of reactive oxygen species. The effect of manganese doping on the structural, biomimetic, and electrocatalytic properties of cyano-bridged assemblies is also discussed.

Field-Effect Capacitors Decorated with Ligand-Stabilized Gold Nanoparticles: Modeling and Experiments.

Nanoparticles are recognized as highly attractive tunable materials for designing field-effect biosensors with enhanced performance. In this work, we present a theoretical model for electrolyte-insulator-semiconductor capacitors (EISCAP) decorated with ligand-stabilized charged gold nanoparticles. The charged AuNPs are taken into account as additional, nanometer-sized local gates.

Electrochemical Cell-based Biosensors for Biomedical Applications.

Electrochemical cell-based biosensors have attracted increasing interest within the last 15 years, with a large number of reports generally dealing with the sensors' sensitivity, selectivity, stability, signal-to-noise ratio, spatiotemporal resolution, etc. However, only a few of them are now available as commercial products. In this review, technological advances, current challenges, and opportunities of electrochemical cell-based biosensors are presented.

Double-Resonant Nanostructured Gold Surface for Multiplexed Detection.

A novel double-resonant plasmonic substrate for fluorescence amplification in a chip-based apta-immunoassay is herein reported. The amplification mechanism relies on plasmon-enhanced fluorescence (PEF) effect. The substrate consists of an assembly of plasmon-coupled and plasmon-uncoupled gold nanoparticles (AuNPs) immobilized onto a glass slide.

Towards Multi-Analyte Detection with Field-Effect Capacitors Modified with Bioparticles as Enzyme Nanocarriers.

Utilizing an appropriate enzyme immobilization strategy is crucial for designing enzyme-based biosensors. Plant virus-like particles represent ideal nanoscaffolds for an extremely dense and precise immobilization of enzymes, due to their regular shape, high surface-to-volume ratio and high density of surface binding sites. In the present work, (TMV) particles were applied for the co-immobilization of penicillinase and urease onto the gate surface of a field-effect electrolyte-insulator-semiconductor capacitor (EISCAP) with a p-Si-SiO-TaO layer structure for the sequential detection of penicillin and urea.

The Structure of the Electric Double Layer of the Protic Ionic Liquid [Dema][TfO] Analyzed by Atomic Force Spectroscopy.

Protic ionic liquids are promising electrolytes for fuel cell applications. They would allow for an increase in operation temperatures to more than 100 °C, facilitating water and heat management and, thus, increasing overall efficiency. As ionic liquids consist of bulky charged molecules, the structure of the electric double layer significantly differs from that of aqueous electrolytes.

An Array of On-Chip Integrated, Individually Addressable Capacitive Field-Effect Sensors with Control Gate: Design and Modelling.

The on-chip integration of multiple biochemical sensors based on field-effect electrolyte-insulator-semiconductor capacitors (EISCAP) is challenging due to technological difficulties in realization of electrically isolated EISCAPs on the same Si chip. In this work, we present a new simple design for an array of on-chip integrated, individually electrically addressable EISCAPs with an additional control gate (CG-EISCAP). The existence of the CG enables an addressable activation or deactivation of on-chip integrated individual CG-EISCAPs by simple electrical switching the CG of each sensor in various setups, and makes the new design capable for multianalyte detection without cross-talk effects between the sensors in the array.