Fully Inkjet-Printed Chemiresistive Sensor Array Based on Molecularly Imprinted Sol–Gel Active Materials

Abstract

The fabrication of chemiresistive sensors by inkjet printing is recognized as a breakthrough in gas-sensing applications. One challenge of this technology, however, is how to enhance the cross-selectivity of the sensor array. Herein, we present a ketjen black (KB) ink and molecularly imprinted sol−gel (MISG) inks to support the fabrication of a fully inkjet-printed chemiresistive sensor array, enabling the highly accurate recognition of volatile organic acids (VOAs) on the molecular level. The MISG/KB sensor array was prepared on a glossy photographic paper with a three-layer structure: a circuit layer by a commercial silver ink, a conductive layer by a KB ink, and an active selective layer by MISG inks imprinted by different templates. Hexanoic acid (HA), heptanoic acid, and octanoic acid were used as templates to prepare the MISGs and as targets to evaluate the detection and discrimination performance of the sensor array. Three resultant MISG/KB sensors exhibited high sensitivity and selectivity to VOA vapors. The limit of detection and imprinting factor were 0.018 ppm and 7.82, respectively, for HA-MISG/KB sensors to the corresponding target. With linear discriminant analysis of the gas responses, the MISG/KB sensor array can realize high discrimination to VOAs in single and binary mixtures. Furthermore, the proposed sensor array showed strong sensor robustness with excellent consistency, durability, bending, and humidity resistance. This work developed a fully inkjet-printed chemiresistive sensor array, enabling the realization of high cross-selectivity detection, achieving low-cost, scalable, and highly reproducible sensor fabrication, moving it closer to reliable, commercial, and wearable multi-analyte human body odor analysis potential.

A Review of Paper-Based Sensors for Gas, Ion, and Biological Detection

“…Xiao Ye et al [63] presented ketjen black (KB) ink and molecularly imprinted sol-gel (MISG) inks for the fabrication of a fully inkjet-printed chemiresistive sensor array to detect volatile organic acids (VOAs). The MISG/KB sensor was fabricated on photographic paper with a three-layer structure.…”

“…The LOD was about 0.018 ppm. [63] Pap@CNT-NH 2 @PPy (minophenylmodified multiwalled carbon nanotubes)…”

“…Several researchers who have reported on sensing materials often solely attribute sensor performance to factors such as sensitivity and/or limit of detection, without considering the impact of the sensors' mechanical properties. Several researchers, including Hao Kan et al [58], Loukkose et al [60], Weiyu Zhang et al [62], Xiao Ye et al [63], and Guh-Hwan Lim et al [65], have reported the sensor's mechanical properties for detecting gas.…”

Preparation of CO2-Responsive Biobased Ternary Composite Microgel and Its Application in Reservoir Gas Channeling Plugging

“…These external stimuli include light, temperature, , pH, , magnetic field, , etc. These materials have high application value and broad application prospects, , such as controllable drug delivery, − intelligent sensors, catalytic control, and so on.…”

Single Phase Transition Leads to the Nanoparticle Deposition in an Evaporating Sessile Droplet

“…Evaporation of a sessile droplet leading to deposition of the dissolved or dispersed solid on the substrate surface continues to be technologically significant and scientifically intriguing. For example, inkjet printing of liquid droplets drives technology such as printed electronics, solar cells, chemical sensors, supercapacitors, display pixels, wearable, flexible, and stretchable devices . In healthcare applications such as printing of biomolecular sensing elements, DNA microarrays and cells (including stem cells), tissue engineering, and regenerative medicine, similar principles are used for depositions of target moieties.…”