Super-Resolution Optical Subtraction Microscopy Using Optical Scattering Imaging

The existing form of super-resolution microscopy based on specific fluorescent tagging is unable to obtain super-resolution images of non-fluorescent samples. Hence, we have developed optical subtraction microscopy for obtaining super-resolution imaging in such cases. This method is based on image subtraction between the two optical scattering images from general confocal excitation and doughnut-shaped excitation, respectively. Unlike super-resolution fluorescence microscopy, subtraction microscopy requires no preprocessing of the sample, and the excitation power can be kept low to avoid sample damage. The non-fluorescent imaging of gold nanobeads and polymer nanofibers has been realized to demonstrate the feasibility of super-resolution subtraction microscopy. The lateral resolution decreases to 215 nm (0.33 lambda, 1 lambda = 650 nm) in subtraction imaging, and greater imaging detail of the sample is achieved via optical scattering.