Related Experiment Video
Updated: Apr 18, 2026
07:17
Aversive Associative Learning and Memory Formation by Pairing Two Chemicals in Caenorhabditis elegans
Published on: June 23, 2022
3.1K
Stable Synapse-Like Memory Switching in N-Heterocyclic Carbene Monolayers
Ankita Das1, Alessandro Borrini2, Christian Gutheil1
1Organisch-Chemisches Institut, University of Münster, Münster, Germany.
Angewandte Chemie (International Ed. in English)
|April 17, 2026
Summary
Researchers developed a redox-active N-heterocyclic carbene (NHC) monolayer exhibiting synapse-like functions. This proton-coupled electron transfer (PCET) mechanism enables molecular-level neuromorphic computing.
Area of Science:
- Molecular Electronics
- Neuromorphic Computing
- Supramolecular Chemistry
Background:
- N-heterocyclic carbenes (NHCs) are versatile ligands with tunable electronic properties.
- Proton-coupled electron transfer (PCET) is a fundamental process in chemistry and biology.
- Neuromorphic computing aims to mimic the structure and function of the human brain.
Purpose of the Study:
- To engineer a robust redox-active NHC monolayer for neuromorphic applications.
- To investigate the synapse-like behavior of functionalized NHCs.
- To demonstrate molecular-level control over electronic states via PCET.
Main Methods:
- Fabrication of self-assembled monolayers (SAMs) of quinone-functionalized NHCs (Rex-NHC) on gold surfaces.
- Characterization using cyclic voltammetry, X-ray photoelectron spectroscopy, and vibrational spectroscopies.
- Construction and testing of molecular junctions (Au-Rex-NHC//Ga2O3/EGaIn).
Main Results:
- Densely packed, upright Rex-NHC SAMs were successfully formed and characterized.
- Molecular junctions exhibited stable operation over ±2 V with high electric field tolerance.
- Bias-induced PCET demonstrated reversible switching between quinone (off) and hydroquinone (on) states.
- Devices showed significant on/off ratios (up to 1.9 × 10^2) and plasticity (spike-timing and spike-rate-dependent).
Conclusions:
- A novel redox-active NHC monolayer displaying robust synapse-like behavior driven by PCET was developed.
- This work establishes NHCs as effective anchoring groups for molecular-level neuromorphic devices.
- The findings open new avenues for designing advanced molecular electronic components.
Related Concept Videos
01:26Chemical Synapses
12.8K
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
12.8K
01:26Chemical Synapses
10.7K
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
10.7K
01:23Role of Neurotransmitters in Memory
3.0K
Neurotransmitters are integral to the brain's communication system, enabling neurons to transmit signals across synapses. This chemical exchange underpins various cognitive functions, including memory processes. The role of neurotransmitters in memory is multifaceted, influencing the encoding, consolidation, and retrieval of memories through their action on different neural circuits.
Glutamate and Synaptic Plasticity
Glutamate, the brain's main excitatory neurotransmitter, is...
Glutamate and Synaptic Plasticity
Glutamate, the brain's main excitatory neurotransmitter, is...
3.0K
01:09Synaptic Signaling
7.2K
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
7.2K
02:26SN2 Reaction: Transition State
13.3K
An SN2 reaction of an alkyl halide is a single-step process in which bond formation between the nucleophile and the substrate and bond breaking between the substrate and the halide occurs simultaneously through a transition state without forming an intermediate.
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
13.3K
01:14Role of Cerebellum and Prefrontal Cortex in Memory
1.6K
The cerebellum, while traditionally associated with motor control, also plays a crucial role in memory, particularly in procedural memory, which involves learning motor tasks that become automatic through repetition. For example, studies have shown that when the cerebellum is damaged, individuals or animals lose the ability to learn conditioned motor responses, such as the conditioned eye-blink response in classical conditioning experiments with rabbits. This study demonstrates the...
1.6K