Respiratory syncytial virus (RSV) is a major cause of acute respiratory tract infections in infants and elderly individuals, leading to hospitalisation and potentially fatal outcomes, posing a serious threat to global health and economy. This study proposes a smartphone-based mobile digital pressure sensor (smartphone-MDPS) for the quantitative detection of the RSV fusion protein (RSV-F) in clinical nasopharyngeal samples. The smartphone-MDPS utilized two monoclonal antibodies (mAbs) specific to the F protein, of which mAb1 was conjugated with Au@PtNPs (Au@PtNPs-mAb1) as the detection antibody and mAb2 was coupled with magnetic beads (MB-mAb2) as a coating antibody to establish a novel sandwich immunoassay. During the immune reaction, the substrate H