Krull, Ulrich J.

Ph.D. | Professor | Chemistry | Biological and Bioanalytical Chemistry

Contact Information

905 828 5437
905 569 4388
Mailing Address: 
3359 Mississauga Road
Postal Code: 
L5L 1C6
Ulli Krull Picture

Research Areas:

Nanotechnology and fluidics for bioassays and theranostics

Krull Research Picture

Research Profile:

Luminescence from nanoparticles (NPs) can be used to interrogate selective interactions at the surface of the nanoparticles by means of resonance energy transfer to a fluorescent label that serves to transduce a binding interaction. Selectivity can be established using immobilized biomolecules on nanoparticles for interaction with proteins, peptides and nucleic acid sequences. Multiplexed solid-phase bioassays on paper-based platforms would be useful technology for rapid detection of markers for pathogens and genetically-based disease. Samples can be manipulated using microfluidics for extraction, concentrating and delivery to the detection system. Our exploration of a combination of various approaches to achieve signal enhancement have allowed use of cell phone cameras as spectrally-selective detectors. We are also exploring the use of upconversion for the photo-controlled intracellular release of drugs. In this approach the NP acts as a platform to cage the therapeutic compound, and to convert near-infrared excitation light to UV-vis emission for photolytic cleavage. The therapeutic compound can be released while the NP concurrently provides the capability to bioassay molecular markers in the sample.

Courses Taught:

CHM414H5 (undergraduate); CHM1103H, CHM1105H, CHM1152H, CHM1157H (graduate)


Uddayasankar, U. and U.J. Krull. 2015. Energy Transfer Assays Using Quantum Dot-Gold Nanoparticle Complexes: Optimizing Oligonucleotide Assay Configuration Using Monovalently Conjugated Quantum Dots, Langmuir, 31: 8194-8204.

Doughan, S., U. Uddayasankar and U.J. Krull. 2015. A paper-based resonance energy transfer nucleic acid hybridization assay using upconversion nanoparticles as donors and quantum dots as acceptors, Analytica Chimica Acta, 878: 1-8.

Noor, M.O. and U.J. Krull. 2014. Camera-based ratiometric fluorescence transduction of nucleic acid hybridization with reagentless signal amplification on a paper-based platform using immobilized quantum dots as donors, Analytical Chemistry, 86: 10331-10339.

Fedoryshin, L.L., A.J. Tavares, E. Petryayeva, S. Doughan and U.J. Krull. 2014. Near-infrared triggered anticancer drug release from upconverting nanoparticles, ACS Applied Materials and Interfaces, 6: 13600-13606.

Zhou, F. and U.J. Krull. 2014. Spectrally matched duplexed nucleic acid bioassay using two-colors from a single form of upconversion nanoparticle, Analytical Chemistry, 86:10932-10939.

Uddayasankar, U. and U.J. Krull. 2013. Analytical performance of molecular beacons on surface immobilized gold nanoparticles of varying size and density, Analytica Chimica Acta, 803: 113-122.

Noor, M.O. and U.J. Krull. 2013. Paper-based Solid-Phase Multiplexed Nucleic Acid Hybridization Assay With Tunable Dynamic Range Using Immobilized Quantum Dots as Donors in Fluorescence Resonance Energy Transfer, Analytical Chemistry, 85: 7502-7511.

Tavares, A.J., M.O. Noor, C.H. Vannoy, W.R. Algar and U.J. Krull. 2012. On-Chip Transduction of Nucleic Acid Hybridization Using Spatial Profiles of Immobilized Quantum Dots and Fluorescence Resonance Energy Transfer, Analytical Chemistry, 84: 312-319.

Chong, L., C.H. Vannoy, M.O. Noor and U.J. Krull. 2012. Intracellular nucleic acid interactions facilitated by quantum dots: Conceptualizing theranostics, Therapeutic Delivery, 3: 479-499.

Chen, L., W.R. Algar, A.J. Tavares and U.J. Krull. 2011. Toward a solid-phase nucleic acid hybridization assay within microfluidic channels using immobilized quantum dots as donors in fluorescence resonance energy transfer. Analytical and Bioanalytical Chemistry, 399: 133-141.

Algar, W.R. and U.J. Krull. 2011. Characterization of the adsorption of oligonucleotides on mercaptopropionic acid-coated CdSe/ZnS quantum dots using Fluorescence Resonance Energy Transfer. Journal of Colloid and Interface Science, 359: 148-154.