The present disclosure discloses a microfluidic cartridge (100) for enriching a biological fluid of low viscosity. The cartridge (100) includes a base plate (1) and a coverslip (5) positioned above the base plate (1), to define a chamber (2) for receiving the biological fluid containing a plurality of particles (10), where the chamber (2) is defined with a predefined height. An inlet section (3a) is defined at one end (4a) of the chamber (2) for introducing the biological fluid and an outlet section (3b) is defined at another end (4b) opposite to the one end. The plurality of particles (10) is enriched about the predefined height of the chamber (2), under action of gravity over a predefined time. The configuration of the cartridge (100) enables formation of monolayer and uniform distribution of the plurality of particles in the biological fluid.