A pregnancy test strip for detection of pathogenic bacteria by using concanavalin A-human chorionic gonadotropin-Cu3(PO4)2 hybrid nanoflowers, magnetic separation, and smartphone readout.

Pregnancy test strips are widely used in daily life. A commercial pregnancy test strip was modified to obtain a point-of-care device for the detection of pathogenic bacteria. Hybrid nanoflowers were prepared from concanavalin A, human chorionic gonadotropin, and Cu3(PO4)2 via a one-pot method. They were used as signaling probes in an off-the-shelf pregnancy test strip. This modified lateral flow immunoassay can detect Escherichia coli O157:H7 with a detection limit of 4 CFU·mL-1, and Salmonella typhimurium with a detection limit of 3 CFU·mL-1. Conceivably, the method has high potential as a portable and cost-effective tool for rapid determination of a wide range of analytes, especially in resource-constrained settings. Graphical abstract Hybrid nanoflower loaded human chorionic gonadotropin (hCG) and concanavalin A (hCG - nanoflowers) were synthesized via a one-pot method and used as signal labels with commercial commercial-off-the-shelf pregnancy test strips to detect pathogenic bacteria targets, thus yielding an easily smartphone readout signal.