Continuous injection synthesis of indium arsenide quantum dots emissive in the short-wavelength infrared

Abstract

With the emergence of applications based on short-wavelength infrared light, indium arsenide quantum dots are promising candidates to address existing shortcomings of other infrared-emissive nanomaterials. However, III–V quantum dots have historically struggled to match the high-quality optical properties of II–VI quantum dots. Here we present an extensive investigation of the kinetics that govern indium arsenide nanocrystal growth. Based on these insights, we design a synthesis of large indium arsenide quantum dots with narrow emission linewidths. We further synthesize indium arsenide-based core-shell-shell nanocrystals with quantum yields up to 82% and improved photo- and long-term storage stability. We then demonstrate non-invasive through-skull fluorescence imaging of the brain vasculature of murine models, and show that our probes exhibit 2–3 orders of magnitude higher quantum yields than commonly employed infrared emitters across the entire infrared camera sensitivity range. We anticipate that these probes will not only enable new biomedical imaging applications, but also improved infrared nanocrystal-LEDs and photon-upconversion technology.

Optical windows for head tissues in near‐infrared and short‐wave infrared regions: Approaching transcranial light applications

“…Over the last decades, the optical tissue transparency window in NIR‐I has been employed for noninvasive optical bioimaging of small animals in biomedical research , advancing the development of imaging guided phototherapy and drug delivery . Quite recently, in addition to the conventional NIR‐I window, two or more optical windows have been identified, namely NIR‐II (~1000‐1350 nm) and NIR‐III or short‐wave IR (SWIR) (~1550‐1870 nm) .…”

“…In particular, NIR‐I and NIR‐II windows have been shown to be suitable for the through‐skull brain imaging in vivo . Moreover, few recent studies have found that light in SWIR (or NIR‐III) window has even better tissue permeability , that makes it advantageous for the imaging utilizing exogenous and endogenous agents .…”

“…Therein, this spectral window centered at 2200 nm has been termed as NIR‐IV window . In the current article, we term it as SWIR‐II, since SWIR is used more frequently in recent years , apparently due to a rapid progress in the development of the SWIR detectors . SWIR‐II window demonstrate a promising potential for brain imaging in comparison with NIR‐II one in terms of collimated/ballistic light permeability .…”

Shortwave infrared fluorescence imaging with the clinically approved near-infrared dye indocyanine green

“…Increasing the quantum yield, functionality, and biocompatibility of SWIR fluorophores is an active focus of emerging research studies (24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41).…”

Advanced NIR‐II Fluorescence Imaging Technology for In Vivo Precision Tumor Theranostics

“…Other D-A-D structured systems and www.advancedsciencenews.com www.advtherap.com [59] SWCNTs-cholate 808/900-1500 0.4 Intravital tumor vessels imaging RGD peptide [5] Chiral SWCNTs 725/850-1350 -Vascular imaging Non-specific [60] QDs Ag 2 S-6PEG 808/1200 15.5 4T1 tumor xenograft imaging, lymphatic drainage, imaging, angiogenesis imaging, brain tumor surgery Non-specific [14,36,38] Ag 2 S-DSPE-PEG 808/1100 -Tumor vessel imaging, image-guided drug delivery cRGD, Ald [45,46] Ag 2 S@SiO 2 785/1135 22.7 NIR-II tumor imaging cRGDfK-R6G peptide [61] InAs-CdSe-CdS 785/1080 16 Non-invasive through-skull fluorescence imaging of the brain vasculature of murine models Non-specific [62] PA-NIRQD 910/1200 >10 Colon cancer imaging MMP-2 activation [43] RENPs Imaging of blood vasculature in the mouse brain and hindlimb Non-specific [29] Organic fluorophores CH1055 980/1055 0.3 Imaging of lymphatic vasculature, orthotopic glioblastoma and brain tumor, and guiding surgery Several major aspects need more attention.…”