监测化学品水平对于保护环境和公众健康至关重要。氨含量升高,例如,会伤害人类和水生生态系统,通常表明农业污染,工业,或污水。开发便携式,高分辨率,因此,对氨进行原位监测的负担得起的方法势在必行。等离子体传感器提供了一个有前途的解决方案,通过将其光学响应的变化与目标分析物的浓度相关联来检测氨。虽然它们非常敏感,可以以各种便携式和用户友好的格式制造,有些仍然需要试剂或昂贵的光学设备,这阻碍了它们的广泛采用。这里,我们提出了一种能够直接检测水性基质中氨浓度的自组装纳米等离子体比色传感器。所提出的传感器利用纳米结构的等离子体共振将化学环境的变化转化为颜色的变化,提供实时分析的无标签方法。该传感器使用自组装技术制造,该技术与基于铝和氧化铝的低成本批量生产兼容,确保可负担性并避免使用其他有毒化学品。我们开发了一个模型,根据传感器的可见颜色变化来预测氨浓度,达到8.5ppm的检测限。此外,为了解决现场检测的需要,我们集成了智能手机技术,用于实时颜色变化分析,消除了对昂贵的需求,笨重的光学仪器。的确,我们的方法提供了一个具有成本效益的,便携式,和用户友好的解决方案,用于水中的氨检测,而无需化学试剂或光谱仪,使其成为理想的现场应用。有趣的是,该平台将其适用性扩展到氨检测之外,使用智能手机监控各种化学物质,不需要任何额外的昂贵的设备。
Monitoring chemical levels is crucial for safeguarding both the environment and public health. Elevated levels of ammonia, for instance, can harm both humans and aquatic ecosystems, often indicating contamination from agriculture, industry, or sewage. Developing portable, high-resolution, and affordable methods for in situ monitoring of ammonia is thus imperative. Plasmonic sensors offer a promising solution, detecting ammonia by correlating changes in their optical response to the target analyte\'s concentration. While they are highly sensitive and can be fabricated in a variety of portable and user-friendly formats, some still require reagents or expensive optical equipment, which hinder their widespread adoption. Here, we present a self-assembled nanoplasmonic colorimetric sensor capable of directly detecting ammonia concentrations in aqueous matrices. The proposed sensor exploits the plasmonic resonance of the nanostructures to transduce changes in the chemical environment into alterations in color, offering a label-free method for real-time analysis. The sensor is fabricated using a self-assembling technique compatible with low-cost mass production based on aluminum and aluminum oxide, ensuring affordability and avoiding the use of other toxic chemicals. We developed a model to predict ammonia concentrations based on visible color change of the sensor, achieving a detection limit of 8.5 ppm. Furthermore, to address the need for on-site detection, we integrated smartphone technology for real-time color change analysis, eliminating the need for expensive, bulky optical instruments. Indeed, our approach offers a cost-effective, portable, and user-friendly solution for ammonia detection in water without the need for chemical reagents or spectrometers, making it ideal for field applications. Interestingly, this platform extends its applicability beyond ammonia detection, enabling the monitoring of various chemicals using a smartphone, without the need for any additional costly equipment.