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19. Spatially Resolved Quantum Sensing with High-Density Bubble-Printed Nanodiamonds

Author

Blankenship, Brian W, Li, Jingang, Jones, Zachary, Parashar, Madhur, Zhao, Naichen, Singh, Harpreet, Li, Runxuan, Arvin, Sophia, Sarkar, Adrisha, Yang, Rundi, Meier, Timon, Rho, Yoonsoo, Ajoy, Ashok, and Grigoropoulos, Costas P

Subjects
Quantum Physics, Engineering, Physical Sciences, Bioengineering, NV centers, Nanodiamonds, Bubble Printing, Quantum Sensing, Magnetic Resonance Imaging, Thermometry, Nanoscience & Nanotechnology
Abstract

Nitrogen-vacancy (NV-) centers in nanodiamonds have emerged as a versatile platform for a wide range of applications, including bioimaging, photonics, and quantum sensing. However, the widespread adoption of nanodiamonds in practical applications has been hindered by the challenges associated with patterning them into high-resolution features with sufficient throughput. In this work, we overcome these limitations by introducing a direct laser-writing bubble printing technique that enables the precise fabrication of two-dimensional nanodiamond patterns. The printed nanodiamonds exhibit a high packing density and strong photoluminescence emission, as well as robust optically detected magnetic resonance (ODMR) signals. We further harness the spatially resolved ODMR of the nanodiamond patterns to demonstrate the mapping of two-dimensional temperature gradients using high frame rate widefield lock-in fluorescence imaging. This capability paves the way for integrating nanodiamond-based quantum sensors into practical devices and systems, opening new possibilities for applications involving high-resolution thermal imaging and biosensing.

Published
2024

25. Plasmodium falciparum heat shock proteins as antimalarial drug targets: An update.

Author

Ahmad, Tanveer, Alhammadi, Bushra, Almaazmi, Shaikha, Arafa, Sahar, Blatch, Gregory, Dutta, Tanima, Gestwicki, Jason, Keyzers, Robert, Shonhai, Addmore, and Singh, Harpreet

Subjects
Antimalarial drugs, Heat shock proteins, Malaria, Molecular chaperones, Plasmodium falciparum, Protein folding, Humans, Heat-Shock Proteins, Plasmodium falciparum, Antimalarials, HSP70 Heat-Shock Proteins, Malaria, Protozoan Proteins
Abstract

Global efforts to eradicate malaria are threatened by multiple factors, particularly the emergence of antimalarial drug resistant strains of Plasmodium falciparum. Heat shock proteins (HSPs), particularly P. falciparum HSPs (PfHSPs), represent promising drug targets due to their essential roles in parasite survival and virulence across the various life cycle stages. Despite structural similarities between human and malarial HSPs posing challenges, there is substantial evidence for subtle differences that could be exploited for selective drug targeting. This review provides an update on the potential of targeting various PfHSP families (particularly PfHSP40, PfHSP70, and PfHSP90) and their interactions within PfHSP complexes as a strategy to develop new antimalarial drugs. In addition, the need for a deeper understanding of the role of HSP complexes at the host-parasite interface is highlighted, especially heterologous partnerships between human and malarial HSPs, as this opens novel opportunities for targeting protein-protein interactions crucial for malaria parasite survival and pathogenesis.

Published
2024

26. Room-temperature quantum sensing with photoexcited triplet electrons in organic crystals

Author

Singh, Harpreet, D'Souza, Noella, Zhong, Keyuan, Druga, Emanuel, Oshiro, Julianne, Blankenship, Brian, Reimer, Jeffrey A., Breeze, Jonathan D., and Ajoy, Ashok

Subjects
Quantum Physics, Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Chemical Physics
Abstract

Quantum sensors have notably advanced high-sensitivity magnetic field detection. Here, we report quantum sensors constructed from polarized spin-triplet electrons in photoexcited organic chromophores, specifically focusing on pentacene-doped para-terphenyl (${\approx}$0.1%). We demonstrate essential quantum sensing properties at room temperature: electronic optical polarization and state-dependent fluorescence contrast, by leveraging differential pumping and relaxation rates between triplet and ground states. We measure high optically detected magnetic resonance (ODMR) contrast ${\approx}16.8\%$ of the triplet states at room temperature, along with long coherence times under spin echo and CPMG sequences, $T_2{=}2.7\mu$s and $T_2^{DD}{=}18.4\mu$s respectively, limited only by the triplet lifetimes. The material offers several advantages for quantum sensing, including the ability to grow large ($cm$-scale) crystals at low cost, the absence of paramagnetic impurities, and the diamagnetism of electronic states used for sensing when not optically illuminated. Utilizing pentacene as a representative of a broader class of spin triplet-polarizable organic molecules, this study highlights new potential for quantum sensing in chemical systems.

Published
2024

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