Solid-state ammonia sensor based on Berthelot’s reaction

✍ Scribed by King Tong Lau; Steve Edwards; Dermot Diamond

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 130 KB
• Volume: 98
• Category: Article
• ISSN: 0925-4005
• DOI: 10.1016/j.snb.2003.08.004

✦ Synopsis

A non-reversible solid-state ammonia sensor based on formation of indophenol blue has been developed. A new optimised reaction conditions found for Berthelot's reaction allow the sensor to respond to dissolved ammonia in ambient conditions at a much faster reaction rate than previously known. This solid-state colorimetric sensor reaches maximum colour intensity in ∼3 min at room temperature (∼20 • C) and responds linearly to ammonia between 1 and 10 ppm. A semi-automatic imaging system that consists of a black and white digital camera illuminated by red, green and blue LEDs was developed to measure the sensor responses.