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.

Compositions and processes are provided for the robust detection of hepatitis C virus in a sample. Compositions include amino acid sequences of HCV core region including or exclusive to residues 14-31 or 50-90 of the HCV core protein. Also provided are processes of detecting HCV in a sample whereby the provided peptides are optionally used alone or in conjunction with antibodies that do not recognize the peptides so that detection is independent of seroconversion in a subject. Using the compositions and processes, HCV can be detected in a sample prior to or following seroconversion leading to robust HCV detection and diagnosis.