Biological sensing and control of emission dynamics of quantum dot bioconjugates using arrays of long metallic nanorods

Abstract

We study biological sensing using plasmonic and photonic-plasmonic resonances of arrays of ultralong metallic nanorods and analyze the impact of these resonances on emission dynamics of quantum dot bioconjugates. We demonstrate that the LSPRs and plasmonic lattice modes of such array can be used to detect a single self-assembled monolayer of alkanethiol at the visible (550 nm) and near infrared (770 nm) range with well resolved shifts. We study adsorption of streptavidin-quantum dot conjugates to this monolayer, demonstrating that formation of nearly two dimensional arrays of quantum dots with limited emission blinking can lead to extra well-defined wavelength shifts in these modes. Using spectrally-resolved lifetime measurements we study the emission dynamics of such quantum dot bioconjugates within their monodispersed size distribution. We show that, despite their close vicinity to the nanorods, the rate of energy transfer from these quantum dots to nanorods is rather weak, while the plasmon field enhancement can be strong. Our results reveal that the nanorods present a strongly wavelength or size-dependent non-radiative decay channel to the quantum dot bioconjugates.

Plasmonic Hot‐Electron‐Induced Control of Emission Intensity and Dynamics of Visible and Infrared Semiconductor Quantum Dots

“…Since smaller QDs can transfer their energies to QDs with larger cores, their lifetimes are shorter. [ 42,43 ] Considering this, the reason that PbS QDs on Si/Al oxide decay faster than those on Si can be partially associated with the spectral redshift of their spectrum (Figure 3a), which further limits the detection of the QD decay.…”

Coherent Networks of Si Nanocrystals: Tunable Collective Resonances with Narrow Spectral Widths

“…[ 9–16 ] The characteristic features of SLRs, including their narrow linewidths, have made them appealing hosts for various applications, including excitonic laser systems, [ 17–19 ] optical filters, [ 20 ] control of the emission of quantum emitters, [ 17,19 ] and biological and chemical sensing. [ 21–23 ]…”

Optically active quadrupole edge modes in arrays of flat metallic nanodisks

“…Additionally, the optical properties of arrays of flat metallic nanoantennas have shown the possibility of hybridization of the edge modes with the Rayleigh anomaly, forming surface lattice resonances (SLRs) [5,19,20]. Recent reports have also investigated the impact of flat metallic nanoantennas on dynamics of excitons in semiconductor quantum dots biologically adsorbed to such nanoantennas, [21,22] and the formation of super-plasmonic cavities in closely-packed flat metallic nanoantennas [23]. Extensive research has also been devoted to plasmonic properties of nanoplates with different shapes, including triangular [24,25], fractal shapes [26,27], and flat metallic nanoantennas made with different materials [28,29].…”