Indefinite and bidirectional near-infrared nanocrystal photoswitching

• Published in: Nature (London) Vol. 618; no. 7967; pp. 951 - 958
• Main Authors: Lee, Changhwan, Xu, Emma Z., Kwock, Kevin W. C., Teitelboim, Ayelet, Liu, Yawei, Park, Hye Sun, Ursprung, Benedikt, Ziffer, Mark E., Karube, Yuzuka, Fardian-Melamed, Natalie, Pedroso, Cassio C. S., Kim, Jongwoo, Pritzl, Stefanie D., Nam, Sang Hwan, Lohmueller, Theobald, Owen, Jonathan S., Ercius, Peter, Suh, Yung Doug, Cohen, Bruce E., Chan, Emory M., Schuck, P. James
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29-06-2023; Nature Publishing Group
• Subjects: 140/125; 631/1647/1888; 639/301/357; 639/624/399/354; 639/638/440/948; 639/925/357/354; Chemical compounds; Data storage; Emissions; Emissions control; Energy transfer; Fluorophores; Genetics; Humanities and Social Sciences; I.R. radiation; Information processing; Light; Localization; MATERIALS SCIENCE; multidisciplinary; Nanocrystals; Nanoparticles; Nanoscale materials; Near infrared radiation; Optical control; Optics; Pharmacology; Photodegradation; Photon avalanches; Point defects; Science; Science (multidisciplinary); Sensors and probes
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/s41586-023-06076-7

Materials whose luminescence can be switched by optical stimulation drive technologies ranging from superresolution imaging
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, nanophotonics
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, and optical data storage
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,
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, to targeted pharmacology, optogenetics, and chemical reactivity
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. These photoswitchable probes, including organic fluorophores and proteins, can be prone to photodegradation and often operate in the ultraviolet or visible spectral regions. Colloidal inorganic nanoparticles
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,
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can offer improved stability, but the ability to switch emission bidirectionally, particularly with near-infrared (NIR) light, has not, to our knowledge, been reported in such systems. Here, we present two-way, NIR photoswitching of avalanching nanoparticles (ANPs), showing full optical control of upconverted emission using phototriggers in the NIR-I and NIR-II spectral regions useful for subsurface imaging. Employing single-step photodarkening
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and photobrightening
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,
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, we demonstrate indefinite photoswitching of individual nanoparticles (more than 1,000 cycles over 7 h) in ambient or aqueous conditions without measurable photodegradation. Critical steps of the photoswitching mechanism are elucidated by modelling and by measuring the photon avalanche properties of single ANPs in both bright and dark states. Unlimited, reversible photoswitching of ANPs enables indefinitely rewritable two-dimensional and three-dimensional multilevel optical patterning of ANPs, as well as optical nanoscopy with sub-Å localization superresolution that allows us to distinguish individual ANPs within tightly packed clusters.
This study reports unlimited near-infrared photoswitching in inorganic avalanching nanoparticles via a discrete shift of threshold intensity mediated by internal defect-based colour centres.