Indian Institute of Science Education and Research, Pune, Dr Homi Bhabha Road, Pune-411008, India.
Nanotechnology. 2019 Mar 8;30(10):105501. doi: 10.1088/1361-6528/aaf83d. Epub 2018 Dec 12.
Ammonia is widely needed in the chemical industry as well as in fertilizers for agriculture. However, in small as well as large quantities, it is not only hazardous for human health but also for our ecosystem. Therefore, ammonia sensing at low concentration with high sensitivity, selectivity and low response time as well as recovery time is important. Here, various nanosensors are fabricated using gold nanoparticles (∼15 nm), silica-gold nanoparticles coreshell particles and coreshell particles embedded in polypyrrol. Comparisons with bare polypyrrol and coreshell particles are also made. In fact, two types of coreshell particles with rod (∼300 nm × 2 μm) shape and spheres (200 nm) of silica were used to anchor gold nanoparticles on them. A comparison showed that silica-gold core-shell particle with silica rods had the highest sensitivity (∼166% @ 130 ppm) amongst all. The sensor is simple to operate (only resistance change is measured), requires no heater as the sensing occurs at room temperature, and showed no response, except for ammonia, to other gases or humidity. It also has a low response time (4 s) and recovery time (10 s) at the lowest (10 ppm) ammonia concentration measured here. Thus, a simple, economical ammonia sensor has been demonstrated here.
氨在化学工业和农业肥料中都有广泛的需求。然而，无论是少量还是大量，它不仅对人类健康，而且对我们的生态系统都有危害。因此，具有高灵敏度、选择性和低响应时间以及恢复时间的低浓度氨传感非常重要。在这里，使用金纳米粒子（约 15nm）、硅-金纳米粒子核壳颗粒和嵌入聚吡咯中的核壳颗粒制造了各种纳米传感器。还与裸聚吡咯和核壳颗粒进行了比较。实际上，使用了两种类型的核壳颗粒，一种具有棒（约 300nm×2μm）形状，另一种具有球形（200nm）的硅，以将金纳米粒子固定在它们上面。比较表明，具有硅棒的硅-金核壳颗粒具有最高的灵敏度（约 130ppm 时为 166%）。该传感器操作简单（仅测量电阻变化），不需要加热器，因为在室温下即可进行感测，并且除了氨之外，对其他气体或湿度没有响应。它在测量的最低（10ppm）氨浓度下也具有低的响应时间（4s）和恢复时间（10s）。因此，这里展示了一种简单、经济的氨传感器。
