Few-Photon Spectral Confocal Microscopy for Cell Imaging Using Superconducting Transition Edge Sensor

Area of Science:

• Photonics
• Microscopy
• Biotechnology

Background:

• Superconducting transition edge sensors (TES) are energy-dispersive single-photon detectors.
• TES can distinguish photon wavelengths from visible to near-infrared (NIR) without spectral dispersive elements.

Purpose of the Study:

• To demonstrate the application of TES for confocal laser scanning microscopy (CLSM).
• To achieve ultra-sensitive, wide-band wavelength range color imaging for biological samples.

Main Methods:

• A TES-based CLSM method was developed and tested on a fluorescence-labeled cell sample stained with three dyes.
• Simultaneous excitation using 405 nm and 488 nm lasers at low power.
• Spectral detection of emission signals by TES into four wavelength bands (blue, green, red, NIR).

Main Results:

• Simultaneous excitation and spectral detection of three dyes were achieved using low laser power (80 and 120 nW).
• TES categorized emission signals into four wavelength bands: up to 500 nm (blue), 500–600 nm (green), 600–800 nm (red), and 800–1,200 nm (NIR).
• RGB color and NIR images of the fluorescent cell sample were captured in a single scan with tens of photon signals per pixel in 40 ms exposure time.

Conclusions:

• TES is a viable wide-band spectral photon detector for life science applications.
• The TES-based CLSM technique offers ultra-sensitive imaging capabilities.
• This method enables detailed spectral and color imaging of biological samples.