Highly Sensitive MXene-Based Micro Quartz Tuning Fork Gas Sensors with Tunable Selectivity — 47a — Wei Ding

Owing to their distinctive morphology, high surface-to-volume ratio, and metal-like electrical conductivity, MXenes have emerged as a highly promising gas-sensing materials. Traditional MXene-based gas sensors predominantly rely on the electrical conductivity of MXenes for signal transduction. However, it is crucial to explore alternative signal transduction mechanisms to fully unlock the potential of MXenes in gas sensing applications. In this study, we have successfully showcased the development of a mass-transduction-based MXene gas sensor, utilizing MXenes as the adaptable receptor and micro quartz tuning fork (MQTF) as the transducer. The interaction between the gas analyte and MXenes induces a change in mass, resulting in a resonant frequency shift of the MQTF. This signal transduction mechanism eliminates the dependency on the electrical conductivity of MXenes, offering a broader range of possibilities for chemical modification of MXenes without concerns about compromising their conductivity. By engineering Ti₃C₂T_x surfaces, we have demonstrated g sensitivity and selectivity tuning of MXene-MQTF gas sensors for detecting CO, SO₂, and NH₃. To our knowledge, this is the first report of an antisymmetric mass-transduction-based (low-cost, stable, sensitive, and practical tuning fork-based) MXene gas sensor, demonstrating exceptional sensing performance, customizable selectivity, and high cost-effectiveness. This study paves the way for designing high-performance MXene-based chemical sensors and expands the scope of potential applications in air quality monitoring, wearable devices, the Internet of Things (IoT), and robotics.

South Dakota State University
Xiaojun Xian