Jiyao Yu

All Publications

• Site-Specific Labeling of PD-L1 Fab through Disulfide Rebridging for ImmunoPET Imaging CHEMICAL & BIOMEDICAL IMAGING Yu, J., Yen, C., Fu, Q., Dai, S., Cheng, M., Rao, J. 2026

  View details for DOI 10.1021/cbmi.6c00022

  View details for Web of Science ID 001710618000001

• Balancing Brightness and Photobasicity: Modulating Excited-State Proton Transfer Pathways in Push-Pull Fluorophores for Biological Two-Photon Imaging. The journal of physical chemistry. A McCallum, A. M., Yu, J., Sumalekshmy, S., Hagwood, A., Fahrni, C. J. 2024; 128 (46): 9904-9916

  Abstract

  Push-pull fluorophores with donor-π-acceptor architectures are attractive scaffolds for the design of probes and labels for two-photon microscopy. Such fluorophores undergo a significant charge-delocalization in the excited state, which is essential for achieving a large two-photon absorption cross-section and brightness. The polarized excited state may, however, also facilitate excited-state proton transfer (ESPT) pathways that can interfere with the probe response. Herein, we employed steady-state and time-resolved spectroscopic studies to elucidate whether ESPT is responsible for the pH-dependent emission response of the Zn(II)-selective fluorescent probe chromis-1. Composed of a push-pull architecture with a pyridine ring as the acceptor, the chromis-1 fluorophore core acts as a photobase that promotes ESPT upon acidification. Although the pKa of the pyridine acceptor increases more than six orders of magnitude upon excitation, the photobasicity is not sufficient to deprotonate solvent water molecules under neutral conditions. Rather, the pH-dependent emission response is caused by the pendant bis-isonicotinic acid chelating group which upon protonation facilitates an excited-state intramolecular proton transfer to the pyridine acceptor. A simple permutation of the core pyridine nitrogen from the para- to the ortho-position relative to the thiazole substituent was sufficient to reduce the excited-state basicity by two orders of magnitude without compromising the two-photon excited brightness. These results highlight the importance of choosing the appropriate fluorophore core and chelating moiety for minimizing pH-dependent responses in the design of fluorescent probes for biological imaging.

  View details for DOI 10.1021/acs.jpca.4c05649

  View details for PubMedID 39508282

  View details for PubMedCentralID PMC11586903

• Conformationally Preorganized High-Affinity Ligands for Copper Biology with Hinged and Rigid Thiophene Backbones INORGANIC CHEMISTRY Yu, J., Bacsa, J., Fahrni, C. J. 2023; 62 (4): 1287-1296

  Abstract

  Copper-selective ligands are essential tools for probing the affinity of cuproproteins or manipulating the cellular copper availability. They also harbor significant potential as antiangiogenic agents in cancer therapy or as therapeutics to combat copper toxicity in Wilson's disease. To achieve the high Cu(I) affinities required for competing effectively with cellular cuproproteins, we recently devised a ligand design based on phosphine-sulfide-stabilized phosphine (PSP) donor motifs. Building on this design strategy, we integrated two PSP donors within preorganized ligand architectures composed of either a hinged bithiophene backbone (bithipPS) or a single rigid thiophene bridge (thipPS). Extensive characterization based on X-ray crystal structures, solution NMR data, spectrophotometric titrations, and electrochemical studies established that bithipPS adapts well to the coordination preferences of Cu(I) to form a discrete air-stable mononuclear Cu(I) complex with a dissociation constant of 4 zM. In contrast, the wider bite angle of thipPS introduces some strain upon Cu(I) coordination to yield an almost 10-fold lower affinity with a Kd of 35 zM. As revealed by ICP-MS and two-photon excitation microscopy studies with the Cu(I)-selective fluorescent probe crisp-17, both ligands are effective at removing cellular copper from live mouse fibroblasts with rapid kinetics. Altogether, the stability and redox properties of PSP-ligand-Cu(I) complexes can be effectively tuned by judicious balancing of their geometrical preorganization and conformational flexibility.

  View details for DOI 10.1021/acs.inorgchem.2c03524

  View details for Web of Science ID 000921813900001

  View details for PubMedID 36661323

  View details for PubMedCentralID PMC10118051

• Halide-Rebound Polymerization of Twisted Amides JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Fu, L., Xu, M., Yu, J., Gutekunst, W. R. 2019; 141 (7): 2906-2910

  Abstract

  The first living polymerization of twisted amides is reported, achieved using simple primary alkyl iodides as initiators. Polymerization occurs through a halide-rebound mechanism in which the nucleophilic twisted amide is quaternized and subsequently ring-opened by the iodide counterion. The covalent electrophilic polymerization generates polymers with living chain ends that are both isolable and stable to ambient conditions, enabling the synthesis of block polymers. This presents a new class of polymers for study that possess high glass transition temperatures and robust thermal stability.

  View details for DOI 10.1021/jacs.8b13731

  View details for Web of Science ID 000459642000022

  View details for PubMedID 30726076

• In Situ Imaging of Zinc with Synthetic Fluorescent Probes ZINC SIGNALING, 2ND EDITION Yu, J., Fahrni, C. J. edited by Fukada, T., Kambe, T. 2019: 365-388

  View details for DOI 10.1007/978-981-15-0557-7_18

  View details for Web of Science ID 000661215000019

• Synthesis of β-keto sulfones <i>via</i> a multicomponent reaction through sulfonylation and decarboxylation ORGANIC CHEMISTRY FRONTIERS Yu, J., Mao, R., Wang, Q., Wu, J. 2017; 4 (4): 617-621

  View details for DOI 10.1039/c7qo00026j

  View details for Web of Science ID 000398911900022

• Generation of Sulfonyl Radicals from Aryldiazonium Tetrafluoroborates and Sulfur Dioxide: The Synthesis of 3-Sulfonated Coumarins ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Zheng, D., Yu, J., Wu, J. 2016; 55 (39): 11925-11929

  Abstract

  A catalyst-free approach for the generation of sulfonyl radicals from aryldiazonium tetrafluoroborates in the presence of DABCO⋅(SO2 )2 is realized. The combination of aryldiazonium tetrafluoroborates, DABCO⋅(SO2 )2 , and aryl propiolates affords 3-sulfonated coumarins in good to excellent yields. This tandem reaction process involves radical addition, spirocyclization, and 1,2-migration of esters. Additionally, the in situ diazotization of a number of anilines allows the directional synthesis of desired 3-sulfonated coumarins in a one-pot, two-step process.

  View details for DOI 10.1002/anie.201607292

  View details for Web of Science ID 000384713100039

  View details for PubMedID 27603499

• <SUP>13</SUP>C NMR spectroscopy of heterocycles: 3,5-diaryl-4-bromoisoxazoles HETEROCYCLIC COMMUNICATIONS Yu, J., Edjah, B., Argueta-Gonzalez, H., Ross, S., Gaulden, P., Shanderson, R., Dave, J., Baumstark, A. L. 2015; 21 (5): 279-283

  View details for DOI 10.1515/hc-2015-0111

  View details for Web of Science ID 000362568300007