A Transparent Nanopatterned Chemiresistor: Visible‐Light Plasmonic Sensor for Trace‐Level NO₂ Detection at Room Temperature

Abstract

The highly selective detection of trace gases using transparent sensors at room temperature remains challenging. Herein, transparent nanopatterned chemiresistors composed of aligned 1D Au–SnO2 nanofibers, which can detect toxic NO2 gas at room temperature under visible light illumination is reported. Ten straight Au–SnO2 nanofibers are patterned on a glass substrate with transparent electrodes assisted by direct‐write, near‐field electrospinning, whose extremely low coverage of sensing materials (≈0.3%) lead to the high transparency (≈93%) of the sensor. The sensor exhibits a highly selective, sensitive, and reproducible response to sub‐ppm levels of NO2, and its detection limit is as low as 6 ppb. The unique room‐temperature NO2 sensing under visible light emanates from the localized surface plasmonic resonance effect of Au nanoparticles, thereby enabling the design of new transparent oxide‐based gas sensors without external heaters or light sources. The patterning of nanofibers with extremely low coverage provides a general strategy to design diverse compositions of gas sensors, which can facilitate the development of a wide range of new applications in transparent electronics and smart windows wirelessly connected to the Internet of Things.

A Fully Integrated Flexible Tunable Chemical Sensor Based on Gold-Modified Indium Selenide Nanosheets

“…Figure f depicts light absorption behavior of InSe and Au-InSe. Consistent with the previous report, the high absorption ability of InSe ranges from UV to near-infrared regions. , A new absorption peak located at ∼550 nm in Au-InSe can be contributed by the localized surface plasmon resonance (LSPR) of Au NPs . Morphologies of sensing films are displayed in Figure S3c–e.…”

“…Figure f shows that the sensing responses to both gases are decent, and the maximum responses were obtained at 20 and 10 wt % of Au loading toward NO 2 and NH 3 , respectively. The reduced response at high Au concentration is likely to do with the enlargement of Au NPs that possibly induces attenuated LSPR, spillover effect, etc . Different from the other sensors’ behavior, 40 wt % Au-InSe/IDEs displayed a positive response to NH 3 .…”

“…However, it should be noted that UV light is harmful to the human body and may damage sensing devices. Additionally, UV light is power consuming and thus not suitable for building wearable or portable devices. , Currently, sunlight and indoor light are also employed. , Despite the energy-efficient advantage, it is hard to guarantee sensor repeatability due to the high dependence of light sources on the external environment. Surface functionalization is an effective way to enhance gas-sensing performance. , Noble metal nanoparticles (NPs) as common zero-dimensional (0D) modifiers have great characteristics including abundant active sites, superior catalytic effect, excellent light absorption ability, and favorable resistance to oxidation. − Using 0D noble metal as a modification reagent of the 2D backbone has been proved to bring about enhanced sensitivity and swift signal recovery for the pristine 2D materials-based gas sensor. , …”

Light-Assisted Enhancement of Gas Sensing Property for Micro-Nanostructure Electronic Device: A Mini Review

“…On the other hand, Kim et al reported the detection of NO 2 gas by a one-dimensional Au-SnO 2 nanofiber sensor under visible light at RT (Lim et al, 2021). The sensor shows a high degree of selectivity, sensitivity and repeatability in response to NO 2 at sub ppm levels.…”

Porous Oxide-Functionalized Seaweed Fabric as a Flexible Breath Sensor for Noninvasive Nephropathy Diagnosis

“…Tremendous developments of the modern industry and smart city have occurred and dramatically changed our life. As the key sensing node of Internet of Things (IoT), gas sensors have attracted extensive attention in wide-ranging fields such as industrial safety, − air pollution monitoring, − hazardous substance alert, − breath analysis, disease diagnosis, − and so on. The development of gas sensors is currently focused on sustainable energy-saving sensors regarding flexible applications. − However, with the progress of these key characteristics, attaining a balance among materials, devices, and power consumption is posing more challenges.…”