  The development of novel strategies for self-assembly in the field of
nanotechnology has witnessed remarkable progress in recent years. Here, we
present a DNA-driven programmable self-assembly to fabricate the targeted
nanophotonic structures. The exploitation of the programmable properties of DNA
and the unique optical properties of QDs unfolds the ability to engineer
complex nanostructures with laser irradiation. The main advantages of this
method are the precise interaction of colloidal quantum dots
(QDs)/nanoparticles (NPs) with the substrate and its reversibility in tuning
the temperature of the medium. Two-dimensional (2D) hierarchical patterns of
QD-ssDNA (ss-single stranded) conjugates were formed over the amine-ssDNA
(NH-ssDNA complementary to the ssDNA conjugated with QDs) coated glass
substrates using the laser (green laser light) radiation for3 or4 h. The
localised heating effect of laser created a dark spot on the substrate where
the laser was irradiated. The optical microscopy images confirmed the effect of
laser irradiation on the coating behaviour of QD-ssDNA conjugates on the
substrate. Further, green-emitting QD-ssDNA were coated onto the hole created
by laser radiation over the red-emitting QD-ssDNA-coated substrate. The optical
properties of DNA-functionalized QDs can be actively controlled on the
complementary DNA-functionalized glass surface by an external optical
excitation. The results of this study demonstrate the potential of light-driven
self-assembly as a powerful tool for fabricating desired nanostructures of
DNA-QD conjugates. This technique holds promise for various applications,
including the development of advanced optical devices, nanophotonic circuits,
and bioengineering systems.
