Non-obstructive intracellular nanolasers

Abstract

Molecular dyes, plasmonic nanoparticles and colloidal quantum dots are widely used in biomedical optics. Their operation is usually governed by spontaneous processes, which results in broad spectral features and limited signal-to-noise ratio, thus restricting opportunities for spectral multiplexing and sensing. Lasers provide the ultimate spectral definition and background suppression, and their integration with cells has recently been demonstrated. However, laser size and threshold remain problematic. Here, we report on the design, high-throughput fabrication and intracellular integration of semiconductor nanodisk lasers. By exploiting the large optical gain and high refractive index of GaInP/AlGaInP quantum wells, we obtain lasers with volumes 1000-fold smaller than the eukaryotic nucleus (Vlaser < 0.1 µm3), lasing thresholds 500-fold below the pulse energies typically used in two-photon microscopy (Eth ≈ 0.13 pJ), and excellent spectral stability (<50 pm wavelength shift). Multiplexed labeling with these lasers allows cell-tracking through micro-pores, thus providing a powerful tool to study cell migration and cancer invasion.

Microlaser-based contractility sensing in single cardiomyocytes and whole hearts

“…Being a purely spectroscopic technique, our method is expected to be more resilient to scattering than imaging-based methods since scattering in biological tissue is elastic and hence does not alter spectroscopic information. By providing single cell specificity, long-term tracking, reduced sensitivity to scattering, and with potential reductions in resonator size [7], microlasers introduce new possibilities for translational approaches that extend well beyond current microscopy-based techniques, offer reduced complexity and impose fewer experimental restrictions.…”

Microlasers Enabled by Soft‐Matter Technology

“…For sensing applications, the ability to produce lasers inside living cells and use them as intracellular probes is unique . Recently, intracellular plasmonic nanolasers, semiconductor nanowires, and nanodisks have also applied for detecting cellular environmental changes and cell‐tagging. Likely, biocompatible and biodegradable materials are highly desired for these applications.…”

Lasing‐Encoded Microsensor Driven by Interfacial Cavity Resonance Energy Transfer

“…Microlasers have emerged as a promising technology, garnering a tremendous amount of attention owing to its potential for use in biomedical and biological applications . Various types of optical microcavities have been developed, such as Fabry–Perot cavities, photonic crystals, and whispering‐gallery‐modes (WGMs), as implemented in ring resonators, micro‐/nanodisks, and microspheres . In particular, microsphere‐based WGM lasers are appealing candidates for sensing probes owing to their convenience, extremely high Q factor, and potential for application in intracellular and extracellular probes .…”