Research Interests

Functional Nanomaterials

Functional Nanomaterials: 

Exploring novel functional nanomaterials, including MXenes, metal-organic frameworks (MOFs), and covalent organic frameworks (COFs), to enable next-generation technologies with enhanced properties and multifunctional capabilities. These advanced materials are utilized in chemical and bio-sensing applications, such as rapid environmental pollutant detection, precise monitoring of health biomarkers, and sensitive diagnostics in clinical settings. Additionally, they significantly enhance performance in energy storage applications by improving electrode materials' conductivity, stability, and electrochemical efficiency, contributing to safer, more durable, and high-capacity batteries.

Hierarchical Colorimetric Sensing Materials: 

We have developed hierarchical colorimetric sensing materials by integrating material properties at different spatial scales to enhance the sensitivity, and minimize humidity and interference effects. These materials imitate nature, which organizes biological tissues in hierarchical structures to achieve complex and sophisticated functions most effectively. The hierarchical colorimetric sensing materials are featured with uniformly formed nano-scaled crystalline sensing sites in the micron-scaled matrix. The hierarchical colorimetric sensing materials approach is universal and wearable-friendly.

Molecularly Imprinted Polymers: 

Molecularly imprinted polymers (MIPs) are synthetic polymer receptors with binding sites that have high affinity and specificity for targeted molecules. The MIPs mimic the natural antibody-antigen systems. Their high selectivity originates from the shapes and functional groups of the cavities in the polymer matrix. We have developed MIPs that are sensitive (ppb level), selective, and stable for organic volatile organic compounds (VOCs) sensing. These MIPs can be used for personal environmental exposure or health biomarker tracking.

Related Publications:

1. Xiaojun Xian, Liying Jiao, Teng Xue, Zhongyu Wu, Zhongfan Liu. Nanoveneers: An Electrochemical Approach to Synthesizing Conductive Layered Nanostructures, ACS Nano, 5, 4000-4006 (2011)

2. Jingjing Yu, Di Wang, Vishal Varun Tipparaju, Francis Tsow, and Xiaojun Xian, Mitigation of Humidity Interference in Colorimetric Sensing of Gases, ACS Sensors, 6, 2, 303-320 (2021)

3. Jingjing Yu, Francis Tsow, Mora, S. Jimena, Vishal Varun Tipparaju, and Xiaojun Xian, Hydrogel-Assisted Colorimetric Sensors with High Humidity Tolerance for Environmental Gases Sensing, Sensors and Actuators B: Chemical, 345, 130404 (2021)

4. Wei Ding, Jingjing Yu. Francis Tsow, Laxmi Jaishi, Buddhi Sagar Lamsal, Rick Kittelson, Sarwar Ahmed, Parashu Kharel, Yue Zhou, Xiaojun Xian*, Highly Sensitive and Reversible MXene-Based Micro Quartz Tuning Fork Gas Sensors with Tunable Selectivity, njp 2D Materials and Applications, 8, 18 (2024) (https://doi.org/10.1038/s41699-024-00452-1)

5. Wei Ding, Jason Sternhagen, Laxmi Raj Jaishi, Parashu Kharel, Xiaojun Xian*, CVD-Synthesized Titanium Carbide Nanoflowers as High-Performance Anode for Sodium-Ion Batteries, Nano Letters, 24, 13324-13332 (2024) (https://doi.org/10.1021/acs.nanolett.4c03597)