▎ 摘　　要

Peripheral blood can provide valuable information on an individual's immune status. Cell-based assays typically target leukocytes and their products. Characterization of leukocytes from whole blood requires their separation from the far more numerous red blood cells.([1]) Current methods to classify leukocytes, such as recovery on antibody-coated beads or fluorescence-activated cell sorting require long sample preparation times and relatively large sample volumes.([2]) A simple method that enables the characterization of cells from a small peripheral whole blood sample could overcome limitations of current analytical techniques. We describe the development of a simple graphene oxide surface coated with single-domain antibody fragments. This format allows quick and efficient capture of distinct WBC subpopulations from small samples (similar to 30 mu L) of whole blood in a geometry that does not require any specialized equipment such as cell sorters or microfluidic devices.