Development of a one-step immunochromatographic strip test using gold nanoparticles for the rapid detection of Salmonella typhi in human serum

► Using gold nanoparticles conjugated with antibody, the limit of detection was lower to be 1.14 × 105 cfu mL−1, which could be visually detected by the naked eye. ► This proposed method uses S. typhi O901 and antibody of S. typhi O901 to give the specific binding of antigens. ► Only one step, S. typhi can be determined in human serum within 15 min by this developed method. ► This strip test offers great promise for a rapid, simple and low-cost analysis of S. typhi.