Synaptic Sensors for Development of Potentiometric NO ₂ Sensors by Using WSe ₂ /PPy Composite Nanoarchitectonics

High Resolution Image Download MS PowerPoint Slide In this study, we report the design of a bioinspired synaptic potentiometric NO 2 sensor based on a WSe 2 /polypyrrole (PPy) nanocomposite, synthesized via a facile liquid-phase exfoliation coupled with an in situ oxidation polymerization process. The resulting core−shell heterostructure exhibits dynamic charge transfer and plasticity behavior, mimicking biological synaptic functions such as potentiation and depression under repetitive gas stimuli. The optimized WSe 2 /PPy (1:1) device displayed an excellent synaptic sensing response of 7.33 at 100 ppb NO 2, with ultrafast response (19 s), recovery (249 s), and an ultralow detection limit of 8.74 ppb at room temperature achieved without any post-annealing treatment. The synergistic interaction between defect-rich WSe 2 and nitrogen-active PPy sites enhanced selective NO 2 adsorption, while DFT analysis confirmed substantial interfacial charge redistribution and band modulation. Moreover, neural network-assisted learning accurately reproduced and predicted synaptic response patterns ( R 2 > 0.99), validating the sensor’s adaptive recognition behavior. This work demonstrates a hybrid material platform bridging neuromorphic sensing and gas detection, opening pathways toward self-learning, low-power synaptic gas sensors for next-generation environmental and health-monitoring systems. The synergistic effects lead to improved sensitivity and rapid response, highlighting its potential for advanced gas sensing applications.