Boosting nanowire chemical sensors with metal-organic frameworks

Detecting trace airborne chemicals is crucial in industrial, agricultural, and medical fields, yet it remains challenging. Existing methods, such as gas chromatography and mass spectrometry, are bulky, expensive, and time-consuming. Alternative approaches using carbon nanostructures or semiconducting materials can solve these problems, but at the expense of selectivity.

John et al. engineered nanostructured metal-organic frameworks (MOFs) over semiconducting nanowire arrays to improve chemical sensitivity and selectivity. Their approach augments the performance of pristine nanowires.

“Semiconducting nanowires are effective gas sensors due to their high surface-to-volume ratio and rapid response to gas molecules,” said author Alishba John. “However, they struggle with selectivity because their sensing mechanism is often based solely on surface interactions, making it challenging to distinguish between different gas types.”

Incorporating MOFs onto the nanowires resulted in more active sites for chemicals to bind with, enhancing the material’s ability to detect trace gases. The tailored structure of the MOF allowed the team to target a specific chemical and avoid cross-selectivity. In tests, the material exhibited increased sensitivity to CO2, methanol, ethanol, acetone, and propane compared to pristine nanowires.

Because MOFs are so versatile, and semiconducting nanowires provide an excellent means of maximizing active sites, the authors envision this type of material will be used in many diverse fields and applications. They plan to focus on sensing applications and continue to refine and develop materials for this purpose.

“Next steps involve the integration of diverse MOF-functionalized arrays of nanowires for engineering electronic noses and sensor networks,” said John.

Source: “Nano-structuring metal organic frameworks on semiconductor nanowire arrays for highly sensitive and selective chemical sensing,” by Alishba T. John, Shiyu Wei, Jodie A. Yuwono, Priyank Kumar, David R. Nisbet, Buddini I. Karawdeniya, Lan Fu, Krishnan Murugappan, and Antonio Tricoli, Applied Physics Reviews (2023). The article can be accessed at https://doi.org/10.1063/5.0153029 .

This paper is part of the Volatile Organic Compounds and their Applications Collection, learn more here .