Jiangxi Key Laboratory of Flexible Electronics and School of Pharmacy, Jiangxi Science & Technology Normal University, Nanchang 330013, China.
Jiangxi Engineering Laboratory of Waterborne Coating, Nanchang 330013, China.
Sensors (Basel). 2023 Mar 14;23(6):3120. doi: 10.3390/s23063120.
Hydrogen peroxide (HO) is commonly used as an oxidizing, bleaching, or antiseptic agent. It is also hazardous at increased concentrations. It is therefore crucial to monitor the presence and concentration of HO, particularly in the vapor phase. However, it remains a challenge for many state-of-the-art chemical sensors (e.g., metal oxides) to detect hydrogen peroxide vapor (HPV) because of the interference of moisture in the form of humidity. Moisture, in the form of humidity, is guaranteed to be present in HPV to some extent. To meet this challenge, herein, we report a novel composite material based on poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) doped with ammonium titanyl oxalate (ATO). This material can be fabricated as a thin film on electrode substrates for use in chemiresistive sensing of HPV. The adsorbed HO will react with ATO, causing a colorimetric response in the material body. Combining colorimetric and chemiresistive responses resulted in a more reliable dual-function sensing method that improved the selectivity and sensitivity. Moreover, the composite film of PEDOT:PSS-ATO could be coated with a layer of pure PEDOT via in situ electrochemical synthesis. The pure PEDOT layer was hydrophobic, shielding the sensor material underneath from coming into contact with moisture. This was shown to mitigate the interference of humidity when detecting HO. A combination of these material properties makes the double-layer composite film, namely PEDOT:PSS-ATO/PEDOT, an ideal sensor platform for the detection of HPV. For example, upon a 9 min exposure to HPV at a concentration of 1.9 ppm, the electrical resistance of the film increased threefold, surpassing the bounds of the safety threshold. Meanwhile, the colorimetric response observed was 2.55 (defined as the color change ratio), a ratio at which the color change could be easily seen by the naked eye and quantified. We expect that this reported dual-mode sensor will find extensive practical applications in the fields of health and security with real-time, onsite monitoring of HPV.
过氧化氢（HO）通常用作氧化剂、漂白剂或防腐剂。在浓度增加时，它也具有危害性。因此，监测 HO 的存在和浓度非常重要，特别是在气相中。然而，许多最先进的化学传感器（例如金属氧化物）由于湿度形式的水分干扰，仍然难以检测到过氧化氢蒸气（HPV）。湿气以湿度的形式在 HPV 中或多或少都会存在。为了应对这一挑战，在此，我们报告了一种基于聚（3,4-亚乙基二氧噻吩）：聚苯乙烯磺酸盐（PEDOT：PSS）掺杂草酸钛铵（ATO）的新型复合材料。这种材料可以作为薄膜在电极衬底上制造，用于 HPV 的化学电阻式传感。吸附的 HO 将与 ATO 反应，导致材料本体发生比色响应。将比色和化学电阻响应相结合，形成了一种更可靠的双功能传感方法，提高了选择性和灵敏度。此外，PEDOT：PSS-ATO 复合膜可以通过原位电化学合成涂覆一层纯 PEDOT。纯 PEDOT 层具有疏水性，将传感器材料下面的部分与湿气隔离开来。这表明在检测 HO 时可以减轻湿度的干扰。这些材料特性的结合使双层复合膜，即 PEDOT：PSS-ATO/PEDOT，成为检测 HPV 的理想传感器平台。例如，在暴露于浓度为 1.9 ppm 的 HPV 9 分钟后，薄膜的电阻增加了三倍，超过了安全阈值。同时，观察到的比色响应为 2.55（定义为颜色变化比），这个比例的颜色变化可以用肉眼轻松看到并进行量化。我们预计，这种报告的双模传感器将在健康和安全领域得到广泛应用，实现 HPV 的实时现场监测。
