A Novel Micro Quartz Tuning Fork-Based Colorimetric Sensor for Monitoring Ammonia Gas — 95a — Laxmi Raj Jaishi

In this study, we report a unique design and performance analysis of a gas sensor based on colorimetric tuning forks (CTFs) that can record mechanical and chemical data from the same sensing event concurrently. The CTF sensor can convert frequency signals from mass changes and optical signals from a colorimetric reaction. We can acquire a wide range of physicochemical characteristics by integrating these two-dimensional (2D) sensor signals into a single CTF unit, improving the accuracy, sensitivity, selectivity, and repeatability of gas detection. By applying bromophenol blue to the prongs of a micro quartz tuning fork (MQTF), which functions as a receptor for ammonia detection, we were able to show the 2D sensing capabilities of the CTF sensor. Our experimental results exhibited that the CTF ammonia sensor has good selectivity and can detect ammonia in the air across a broad range (500 ppb – 1000 ppm) with a detection limit of 500 ppb. Owing to its small size (a few millimeters), lightweight, inexpensive cost (less than $1), easy fabrication method, and superior performance, the CTF sensor is a great option for monitoring ammonia in industries, agricultural fields, wearable technologies and point-of-care diagnostic instruments.

South Dakota State University
Dr. Xiaojun Xian