An official website of the United States government.

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

A Novel, Lightweight, Ammonia Vapor Detector


The primary technical objective of this program is to develop a low-cost, high-performance ammonia detector with wireless networking capabilities and a user-friendly software interface. This portable detection device will afford real-time ammonia vapor measurements which improve current capabilities to monitor the presence and/or diffusion of ammonia vapor throughout agricultural landscapes (crops, livestock waste, etc.). In Phase I we seek to validate, as proof-of-concept, that the proposed Lewis Acid Telechelic Polymer (LATP) chemistry integrated with Seacoast&#39;s proprietary chemicapacitor and chemiresistor technology will demonstrate the required analytical performance as an ammonia vapor detector to justify further development in Phase II.LATPs offer a promising approach to develop sensitive and selective detector materials for ammonia. The tunable binding of ammonia and/or its analogues to a thin-film of a supramolecular LATP hydrogen-bonded matrix causes a change in the bulk film properties, resulting in a concomitant change that can be monitored via resistance or capacitance measurements. This transformation in properties allows the macromolecular LATP system to be exploited as an ammonia-sensitive transducer. Polymer matrices that can be rationally designed to demonstrate enhanced sensitivity to ammonia-based analytes introduces a new paradigm in gas-phase ammonia detection technology. The natural signal transduction that emerges from the disruption of hydrogen-bonding can be leveraged to enhance sensitivity while simultaneously affording a functional handle which can be utilized to monitor gas-phase ammonia exposure in real-time. As real-time measurements of gas-phase ammonia exposure can be exceedingly difficult to collect, even with research grade analytical instrumentation and experienced technical personnel, the fact that these materials can be used to monitor ammonia vapor in real-time is a highly valuable feature. The use of functional LATP nanomaterials as transducing active layers in MEMS chemicapacitors and chemiresistors also facilitates the miniaturization of real-time, ammonia detection without compromising operational performance.The Phase I experiments will focus on demonstrating the sensitivity and stability of the LATP detection platform with ppm-ppb limits of detection, thermal stability from 20°C - 40°C, and variance <5%. The main focuses of the proof-of-concept study are outlined below:Develop novel ammonia sensitive LATPs,Analyze the use of these LATPs as an ammonia detection platform in a controlled environmental chamber,Identify design rules and methods to rationally improve upon the LATP sensitivity,Outline the steps necessary to develop an advanced prototype for Phase II.The Phase I target is the detection of ammonia vapor in the 5-50 ppm range with sufficient resolving power for subsequent selectivity experiments. Seacoast has the team, infrastructure, and resources in place to successfully deliver on these goals. The sensitivity, lifetime, and ruggedness of this detection system will be further optimized in Phase II and a fully functional advanced prototype will be fabricated.Criteria for Success: The project&#39;s success will be demonstrated by our ability to: (1) optimize LATP materials for ammonia detection (2) demonstrate detection of ammonia against likely interferents (H2O, O2, CO2) (3) demonstrate detection of ammonia in a controlled environmental chamber with controlled variable temperature and humidity. (4) elucidate the molecular design rules needed to rationally enhance selectivity and sensitivity of the materials system (5) develop a viable path forward for advanced prototype development for field testing and customer evaluation in Phase II.

Cowart, John
Seacoast Science, Inc.
Start date
End date
Project number
Accession number