Lateral flow immunoassay combined with color saturation for smartphone-based quantitative point-of-care detection of <i>Klebsiella pneumoniae</i>

Abstract Klebsiella pneumoniae is one of the most common pathogenic, multidrug-resistant Gram-negative bacteria that triggers postoperative infections, leading to septic shock and fatality. Therefore, there is an urgent need to generate rapid and sensitive diagnosis techniques for timely and effective intervention. The present work described the fabrication of lateral flow immunoassays (LFIA) based on antibody-gold nanoparticle covalent conjugation combined with an RGB system to detect Klebsiella pneumoniae quantitatively. The LFIAs showed the lines after 15 min with good sensitivity and a low limit of detection of 2.40 CFUs ml −1 in the linear detection range of this immunosensor from 10 1 to 10 8 CFUs ml −1 when combined with the color saturation system. No false positives and cross-reactions were observed on the test strips in this study, indicating that the system was optimized with high specificity. This finding might provide a well-suited solution for a quick, inexpensive, and easy-to-use detection method for potential commercial manufacture.