Image created by Dr. Michael J. Miller
Researchers at National Taiwan University have unveiled an innovative diagnostic tool that significantly improves the speed and accuracy of detecting bacterial infections. This technology is designed to enhance the sensitivity to identify harmful bacteria like Staphylococcus aureus and Pseudomonas aeruginosa, which can cause severe illnesses.
"The goal of our research group is to develop affordable and sensitive detection devices for better personal care," said Prof. Chien-Fu Chen. The research is published in Biosensors and Bioelectronics.
This study uses gold nanoparticles combined with a copper-enhancing chemical reaction to amplify the detection signals effectively, making even minute amounts of bacteria detectable. Unlike traditional methods that require complicated procedures or multiple steps, this test simplifies the process into a single step, delivering results in just 20 minutes.
Researchers created a portable device to ensure precise results, minimizing errors from visual interpretation. This reliable tool performed well in clinical trials, detecting bacteria in complex samples like joint fluid, proving its real-world potential. This breakthrough offers a faster, easier, and more affordable way to diagnose bacterial infections.
Yuh-Shiuan Chien et al, One-step copper deposition-induced signal amplification for multiplex bacterial infection diagnosis on a lateral flow immunoassay device, Biosensors and Bioelectronics (2024). DOI: 10.1016/j.bios.2024.116849.
Abstract
The lateral flow immunoassay (LFIA) is predominant in rapid diagnostic tests owing to its cost-effectiveness and operational simplicity. However, the conventional LFIA exhibits limited sensitivity and is susceptible to human variance for the result readout, impacting result interpretation. In this study, we introduced a novel one-step copper deposition-induced signal amplification lateral flow immunoassay (osa-LFIA) that markedly enhances the detection sensitivity for Staphylococcus aureus (protein A) and Pseudomonas aeruginosa (exotoxin A). Utilizing gold nanoparticles (AuNPs) as a catalyst, this approach employs ascorbic acid to reduce Cu2+ to Cu0, depositing on AuNPs at the test line and amplifying the signal. A user-friendly design features a three-dimensional paper structure incorporating pre-dried reagents, enabling a streamlined, efficient testing process. The osa-LFIA significantly lowers detection limits to 3 ng mL−1 for protein A and 10 ng mL−1 for exotoxin A, offering a tenfold improvement over conventional LFIA. Additionally, we developed a portable grayscale detection device, achieving less than 10% error in quantitative analysis compared to the data acquired and analyzed in the lab. This entire process, from detection to signal amplification, is completed in just 20 min. For the clinical trial, we utilized the osa-LFIA to test synovial fluid samples infected with Staphylococcus aureus. We also successfully detected different concentrations of the exotoxin A in parallel, with a recovery value of 96%–110%. Our findings demonstrate the osa-LFIA's potential as a rapid, highly sensitive, and simple-to-use diagnostic tool for detecting various pathogens, significantly advancing the field of rapid diagnostic testing.