Research at Analytical DNA Nanotechnology Laboratory (ADNL) is at the interface of bioanalytical chemistry and DNA nanotechnology. We consider DNA both as important biomarkers for diverse biological processes and clinical diagnostics and also as a class of highly programmable engineering material. As such, we are interested in developing advanced tools for nucleic acid testing and protein detection at decentralized conditions, such as for point-of-care diagnosis and field-deployable tests. We are also interested in the fundamentals and applications of DNA nanotechnology, where we program DNA into diverse nanodevices and nanomachines with predictable behaviors and function. 

1. New building blocks for dynamic DNA nanotechnology

We aim to enrich the current toolbox of dynamic DNA nanotechnology by introducing new concept and strategies of DNA strand displacement reactions. For example, we recently introduced the idea of allosteric DNA toehold that offers a simple and flexible solution for designing large-scale DNA neural networks. We also introduced a series of protein-responsive DNA toehold strategies that expand the dynamic DNA nanotechnology to proteins. 

代表性论文：

1. Yang, X.; Tang, Y.; Traynor, S. M.; Li, F.* Regulation of DNA strand displacement using allosteric DNA toehold. J. Am. Chem. Soc. 2016, 138, 14076-14082

2. Li, F.*; Tang, Y.; Traynor, S. M.; Li, X.-F.; Le, X. C.* Kinetics of Proximity-Induced Intramolecular DNA Strand Displacement. Anal. Chem. 2016, 88, 152-8157.

3. Tang, Y.; Wang, Z.; Yang, X.; Chen, J.; Liu, L.; Zhao, W.; Le, X. C.; Li, F.* Constructing real-time, wash-free, and reiterative sensors for cell surface proteins using binding-induced dynamic DNA assembly. Chem. Sci. 2015, 6, 5729-5733. 

4. Tang, Y.; Lin, Y.; Yang, X.; Wang, Z.; Le, X. C.; Li, F.* Universal strategy to engineer catalytic DNA hairpin assemblies for protein analysis. Anal. Chem. 2015, 87, 8063-8066. 

5. Li, F.; Zhang, H.; Wang, Z.; Li, X.; Li, X.-F.; Le, X. C. Dynamic DNA assemblies mediated by binding-induced DNA strand displacement. J. Am. Chem. Soc. 2013, 135, 2443-2446.

6. Li, F.; Lin, Y.; Le, X. C. Binding-induced formation of DNA three-way junctions and its application in real-time protein detection and DNA strand displacement. Anal. Chem. 2013, 85, 10835-10841.  

7. Li, F.; Zhang, H.; Lai C.; Li, X-F.; Le, X. C. A molecular translator that acts by binding-induced DNA strand displacement for a homogeneous protein assay. Angew. Chem. Int. Ed. 2012, 51, 9317-9320. 

2. 3D DNA nanomachines

We are also interested in interfacing dynamic DNA nanotechnology with nanomaterials to fabricate 3D machines and devices with well-defined function at nanoscale. We explore such devices as superior analytical tools for applications including biosensing, clinical diagnostics, and biocomputing. By interfacing dynamic DNA nanotechnology with nanomaterials, we also aim to understand the fundamentals of biorecognition and biocatalysis at the biomolecule-nanoparticle interfaces. 

代表性论文：

1. Mason, S. D.; Wang, G. A.; Yang, P.; Li, Y.; Li, F.* Probing and controlling dynamic interactions at biomolecule-nanoparticle interfaces using stochastic DNA walkers. ACS Nano 2019, 13, 8106-8113.

2. Mason, S. D.; Tang, Y.; Li, Y.; Xie, X.; Li, F.* Emerging bioanalytical applications of DNA walkers. Trends in Analytical Chemistry, 2018, 107, 212-221. 

3. Li, Y.; Wang, G. A.; Mason, S. D.; Yang, X.; Yu, Z.; Tang, Y.; Li, F.* Simulation-guided engineering of an enzyme-powered three dimensional DNA nanomachine for discriminating single nucleotide variants. Chem. Sci. 2018, 9, 6434-6439.

4. Li, F.;* Lin, Y.; Lau, A.; Tang, Y.; Chen, J.; Le, X. C.* Binging-induced molecular amplifier as a universal detection platform for biomolecules and biomolecular interaction. Anal. Chem. 2018, 90, 8651-8657. 

5. Yang, X.; Tang, Y.; Mason, S. D.; Chen, J.; Li, F.* Enzyme-powered three-dimensional DNA nanomachine for DNA walking, payload release, and biosensing.  ACS Nano 2016, 10, 2324-2330.

3. New detection platforms for point-of-care testing

Leveraging our expertise in DNA nanotechnology and capability of multi-length-scale engineering, we aim to develop novel diagnostic platforms for the next generation point-of-care tesing. Our platforms are  portable, rapid, and inexpensive, with minimal barriers for technology transfer and adoption. We wish our technologies may help address current changes in global health and personalized medical care. We are also interested in expanding our detection platforms to precision agriculture and animal cares.

代表性论文： 

1. Li, Y.; Mansour, H.; Wang, T.; Poojari, S.; Li, F.* Naked-eye detection of grapevine red-blotch viral infection using a plasmonic CRISPR Cas12a assay. Anal. Chem. 2019, 91, 11510-11513.

2. Dong, T.; Wang, G. A.; Li, F.* Shaping up field-deployable nucleic acid testing using microfluidic paper-based analytical devices. Anal. Bioanal. Chem. 2019, 411, 4401-4414 (invited contribution for the "Young Investigators in (Bio-)Analytical Chemistry" theme collection)

3. Wang, G. A.;^# Dong, T.;^# Mansour, H.; Matamoros, G.; Sanchez, A. L.; Li, F.* Paper-based DNA reader for visualized quantification of soil-transmitted helminth infections. ACS Sensors 2018, 3, 205-210. 

4. Soleymani, L.;* Li, F.* Mechanistic challenges and advantages of biosensor miniaturization into the nanoscale. ACS Sensors 2017, 2, 458-467.