Fig. 1

This schematic illustrates the process of self-collecting NF using the 3DPFS. The 3DPFS is inserted into the nasal cavity and the released NW solution flows into the MT, allowing for the subsequent collection of NF using the swab head with a single large hole. The 3DPFS consists of three parts: the swab head, microchannel, and socket, which are connected to a syringe filled with NW solution. Our study demonstrates that the 3DPFS can collect significantly more NF with relatively less pain compared to CS, making it a promising alternative for COVID-19 testing