Semiconductor quantum dots (QDs), being an auspicious outcome of nanotechnology, have wide technological applications based on their simple synthetic procedures, tunable photoluminescent properties, and effective optical stability. However, their utilization in sensing, imaging, and optoelectronic applications is limited due to their intrinsic drawback of fluorescence intermittency, which not only hinders precise biological imaging due to challenges in tracking individual target molecules but also gives inaccurate measurements and creates complications in data analysis due to long dark (off) states that remain on the time scale of milliseconds to minutes. In order to resolve this problem, research work is being carried out on a large scale to elucidate the mechanism following blinking and approaches to suppress it. This review explicitly highlights the key mechanisms: A type (Auger), B type, near band edge carrier (C type), and D type, responsible for the blinking effect in QDs, and explores the effective methods for its suppression including shell engineering, halide vacancy filling, and passivating the surface with ligands, polymers, noble metals, and plasmonic as well as N-Type semiconductor substrates to enhance their efficiency on practical grounds. Nearly non-blinking QDs with an on-state for 99% of the time have been synthesized by shell engineering. The suppression of blinking leads to improved performance and enhanced efficiency of QD-based devices. According to the literature reports, these methodologies efficiently suppress the blinking phenomenon, even approaching near unity (approximate to 1) photoluminescence quantum yield, which is notable. Finally, the current review discusses the advantages of blinking suppression specifically in biomedical applications such as single particle tracking, in vivo and in vitro imaging, and biosensing.
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Title
Blinking effect in quantum dots, its suppression mechanism, and applications in medical imaging and biosensing
Publication Details
AVS quantum science, Vol.7(2), 021101
Resource Type
Journal article
Publisher
AIP Publishing
Number of pages
30
Grant note
University of Electronic Science and Technology of China (UESTC)