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.

中文翻译：

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基于分子印迹溶胶-凝胶活性材料的全喷墨打印化学电阻传感器阵列

通过喷墨打印制造化学电阻传感器被认为是气体传感应用的一个突破。然而，这项技术的一个挑战是如何增强传感器阵列的交叉选择性。在这里，我们展示了科琴黑 (KB) 墨水和分子印迹溶胶凝胶 (MISG) 墨水，以支持完全喷墨打印的化学电阻传感器阵列的制造，从而能够高度准确地识别分子上的挥发性有机酸 (VOA)等级。MISG/KB 传感器阵列是在具有三层结构的光面相纸上制备的：电路层由商业银墨水制成，导电层由 KB 墨水制成，活性选择层由不同模板印制的 MISG 墨水制成。己酸 (HA)、庚酸、和辛酸被用作模板来制备 MISG，并作为目标来评估传感器阵列的检测和辨别性能。三个合成的 MISG/KB 传感器对 VOA 蒸气表现出高灵敏度和选择性。HA-MISG/KB 传感器对相应目标的检测限和印迹因子分别为 0.018 ppm 和 7.82。通过对气体响应的线性判别分析，MISG/KB 传感器阵列可以实现对单一和二元混合物中的 VOA 的高度区分。此外，所提出的传感器阵列显示出强大的传感器鲁棒性，具有出色的一致性、耐用性、弯曲和耐湿性。本工作开发了一种全喷墨打印的化学电阻传感器阵列，能够实现高交叉选择性检测，实现低成本、可扩展、