Ulrich J. Krull
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E-mail:
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Mailing Address:
3359 Mississauga Road
Mississauga ON L5L 1C6
Canada
Research Areas:
Nanotechnology and fluidics for bioassays and theranostics
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.
Publications
Recent:
K. Malhotra, B. Kumar, P.A.E. Piunno and U.J. Krull, Cellular Uptake of Upconversion Nanoparticles Based on Surface Polymer Coatings and Protein Corona, ACS Materials and Interfaces, 16(28), 35985-36001, 2024.
K. Malhotra, D. Hrovat, B. Kumar, G. Qu, J. Van Houten, R. Ahmed, P.A.E. Piunno, P.T. Gunning and U.J. Krull, Lanthanide-doped Upconversion Nanoparticles: Exploring A Treasure Trove of NIR-Mediated Emerging Applications, ACS Materials and Interfaces, 15(2), 2499-2528, 2023.
K. Malhotra, R. Fuku, B. Kumar, D. Hrovat, J. Van Houten, P.A.E. Piunno, P.T. Gunning and U.J. Krull, Unlocking Long-Term Stability of Upconversion Nanoparticles with Biocompatible Phosphonate-Based Polymer Coatings, Nano Letters, 22, 7285-7293, 2022.
B. Kumar, K. Malhotra, R. Fuku, J. Van Houten, Yue Qu, P.A.E. Piunno and U. J. Krull, Recent Trends in the Developments of Analytical Probes Based on Lanthanide-Doped Upconversion Nanoparticles, Trends in Analytical Chemistry, 139: 116256, 2021.
T. Nguyen, A. Sedighi, U.J Krull and C. Ren, A multi-functional droplet microfluidic platform for rapid immobilization of oligonucleotides on semiconductor quantum dots, ACS Sensors, 5: 746-753, 2020.
A. Shahmuradyan, M. Moazami-Goudarzi, F. Litazume, G.S. Espie and U.J. Krull, Paper-based platform for detection by hybridization using intrinsically labeled fluorescent oligonucleotide probes on quantum dots, The Analyst, 144: 1223-1229, 2019.
P. Das, A. Sedighi and U.J. Krull, Cancer biomarker determination by resonance energy transfer using functional fluorescent nanoprobes, Analytica Chimica Acta, 1041: 1-24, 2018.
Y. Han Y. Han, M.O. Noor, A. Sedighi, U. Uddayasankar, S. Doughan and U.J. Krull, Inorganic Nanoparticles as Donors in Resonance Energy Transfer for Solid-Phase Bioassays and Biosensors, Langmuir, 33: 12839-12858, 2017 (selected for front cover of journal).
A. Shahmuradyan and U.J. Krull, Intrinsically Labeled Fluorescent Oligonucleotide Probes on Quantum Dots for Transduction of Nucleic Acid Hybridization, Analytical Chemistry, 88, 6: 3186-3193, 2016.
S. Doughan, U. Uddayasankar and U.J. Krull, 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, 2015 (selected for cover page as featured article).