The human visual nervous system excels at recognizing and processing external stimuli, essential for various physiological functions. Biomimetic visual systems leverage biological synapse properties to improve memory encoding and perception. Optoelectronic devices mimicking these synapses can enhance wearable electronics, with layered heterojunction materials being ideal materials for optoelectronic synapses due to their tunable properties and biocompatibility. However, conventional synthesis methods are complex and environmentally harmful, leading to issues such as poor stability and low charge transfer efficiency. Therefore, it is imperative to develop a more efficient, convenient, and eco-friendly method for preparing layered heterojunction materials. Here, a one-step ultrasonic method is employed to mix fullerene (C60) with graphene oxide (GO), yielding a homogeneous layered heterojunction composite film via self-assembly. The biomimetic optoelectronic synapse based on this film achieves 97.3% accuracy in dynamic visual recognition tasks and exhibits capabilities such as synaptic plasticity. Experiments utilizing X-ray photoelectron spectroscopy (XPS), X-ray diffraction spectroscopy (XRD), Fourier–transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirms stable π-π interactions between GO and C60, facilitating electron transfer and prolonging carrier recombination times. The novel approach leveraging high-density π electron materials advances artificial intelligence and neuromorphic systems.
Lei Gao,Donghui Kou,Ruicheng Lin,Wei Ma,Shufen Zhang
The photonic nose inspired by the olfactory system is an integrated detection platform constructed by multiple sensing units as channels. However, in the detection of volatile organic compounds (VOCs), the sensing results that cannot be directly readable and the poor ability to distinguish analytes with similar chemical properties are the main challenges faced by this sensor. Here, 8 metal-organic frameworks (MOF)-based photonic crystals are used as the basic sensing units to construct a photonic nose detection platform. The microscopic adsorption of VOCs by MOFs enables the photonic crystals (PCs) to produce macroscopic structural color output, and further makes the photonic nose have specific color fingerprints for different VOCs, the response time of all PCs to VOCs can be within 1 s. Through the color fingerprint, the visual identification of VOCs produced by 5 common solvent vapors is realized, and 9 VOCs with similar chemical properties are further distinguished. In addition, the application potential of the photonic nose in the actual environment is verified by identifying different contents of benzene in the paint. It is envisaged that the MOF-based photonic nose has great reference value for the development of intelligent and multi-component synergistic functional gas sensors.
A room temperature reducing agent-free strategy for the synthesis of a nitrogen-doped graphene quantum dot-silver nanoparticle (N-GQD/AgNP) hybrid was presented. In this strategy, N-GQDs were used as a reducing agent and stabilizer for the formation of the N-GQD/AgNP hybrid, and the formation of the N-GQD/AgNP hybrid may result from the extraordinary reduction properties of N-GQDs, which are attributed to the nature of the surface oxygen-containing functional groups. The N-GQD/AgNP hybrid exhibits good dispersity and outstanding catalytic ability toward the oxidation of catechol (CC) and hydroquinone (HQ) by Ag+. In the presence of the N-GQD/AgNP hybrid, the reduction of Ag+ by CC and HQ was improved. CC enhanced the absorbance of the N-GQD/AgNP-Ag+ system the most, and HQ followed, while resorcinol (RC) had only a little effect on the absorption intensity of the system. Thus, a sensitive and selective colorimetric sensing method based on the N-GQD/AgNP-Ag+ system was developed for the discrimination of CC, HQ and RC. A good linear relationship was obtained from 0.1 to 15.0 μM for CC and from 0.3 to 20.0 μM for HQ. The detection limits of CC and HQ were 0.03 and 0.1 μM, respectively. In addition, the proposed method also shows a high selectivity for the detection of CC and HQ, and appreciable changes in color of the N-GQD/AgNP-Ag+ system toward CC, RC and HQ were observed.
危险品化学品经营许可证（带存储）