The present disclosure in some aspects relates to HCV core antigen polypeptides. In some aspects, the present disclosure further relates to HCV antibodies, including camelid antibodies that specifically bind to HCV core antigen, and antibody fragments. The disclosure further relates to methods of detecting an analyte in a sample using a camelid antibody, such as a camelid VHH antibody or fragments thereof. In one aspect, provided herein is a technology platform for isolating highly specific antibodies and applying these antibodies in an immunoassay, such as a lateral flow immunoassay (LFIA). In some aspects, this technology is used to develop HCV core antigen specific antibodies and to produce LFIA devices for rapid and early diagnosis of HCV. In other aspects, a rapid test is provided for screening and detection of hepatitis C virus infection to improve the diagnosis rate and effectively prevent HCV infection transmission.
