Single-molecule fluorescence imaging detects the emission from individual molecules to reveal their structural and dynamic behaviors, overcoming the limitations of ensemble measurements that obscure molecular heterogeneity. This technique integrates multiple imaging modalities—including point-scanning confocal, TIRF, FRET, and PALM/STORM—to elucidate critical molecular processes such as protein folding, receptor trafficking, and nucleic acid dynamics, and has become an indispensable tool in life science research.

Because single-molecule signals are inherently weak, the experiments impose stringent and diverse demands on the imaging system:

● Point-scanning confocal microscopy emphasizes background suppression and typically uses PMT or GaAsP detectors for signal acquisition.

● Super-resolution techniques such as PALM and STORM rely on high-quantum-efficiency, low-noise cameras to achieve millisecond-scale signal acquisition and nanometer-level localization precision.

● TIRF, FRET, and single-molecule tracking demand high signal-to-noise imaging under low light while capturing millisecond dynamics. These applications also require minimizing photobleaching and phototoxicity, placing high demands on camera sensitivity, speed, and stability.