title: Brightness-equalized quantum dots.
abstract: As molecular labels for cells and tissues, fluorescent probes have shaped our understanding of biological structures and processes. However, their capacity for quantitative analysis is limited because photon emission rates from multicolour fluorophores are dissimilar, unstable and often unpredictable, which obscures correlations between measured fluorescence and molecular concentration. Here we introduce a new class of light-emitting quantum dots with tunable and equalized fluorescence brightness across a broad range of colours. The key feature is independent tunability of emission wavelength, extinction coefficient and quantum yield through distinct structural domains in the nanocrystal. Precise tuning eliminates a 100-fold red-to-green brightness mismatch of size-tuned quantum dots at the ensemble and single-particle levels, which substantially improves quantitative imaging accuracy in biological tissue. We anticipate that these materials engineering principles will vastly expand the optical engineering landscape of fluorescent probes, facilitate quantitative multicolour imaging in living tissue and improve colour tuning in light-emitting devices.
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Lim
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Mohammad U
authors.initials: MU
authors.lastname: Zahid
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Phuong
authors.initials: P
authors.lastname: Le
authors.affiliation: Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Anatomy and Structural Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.|Integrated Imaging Program, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.|Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.
authors.forename: David
authors.initials: D
authors.lastname: Entenberg
authors.affiliation: Department of Anatomy and Structural Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.|Integrated Imaging Program, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.|Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.|Department of Radiology, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.
authors.forename: Allison S
authors.initials: AS
authors.lastname: Harney
authors.affiliation: Department of Anatomy and Structural Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.|Integrated Imaging Program, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.|Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA.
authors.forename: John
authors.initials: J
authors.lastname: Condeelis
authors.affiliation: Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.|Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Smith
mesh_terms: D000818:Animals; D005260:Female; D051379:Mice; D008822:Mice, Transgenic; D046529:Microscopy, Electron, Transmission; D036641:Microscopy, Fluorescence, Multiphoton; D053758:Nanoparticles; D036103:Nanotechnology; D061848:Optical Imaging; D045663:Quantum Dots; D013050:Spectrometry, Fluorescence