Lateral flow immunoassay is a rapid diagnostic point-of-care device prevalently used in different areas especially in clinical diagnosis. Traditional detection methods take few hours for the analysis that is time consuming, lab intensive and inefficient. Lateral flow immunoassays are able to give the results within minutes and do not require skilled technicians to perform the test because of the design of easy read out. In view of the disadvantages of the common colorimetric signaling molecules such as low sensitivity and only qualitative/semi-quantitative results could be achieved. A novel signaling molecule dye-doped silica nanoparticles was synthesized by reverse micro-emulsion. The color of the silica nanoparticles was physically entrapped and no dye leakage was observed af...[ Read more ]

Lateral flow immunoassay is a rapid diagnostic point-of-care device prevalently used in different areas especially in clinical diagnosis. Traditional detection methods take few hours for the analysis that is time consuming, lab intensive and inefficient. Lateral flow immunoassays are able to give the results within minutes and do not require skilled technicians to perform the test because of the design of easy read out. In view of the disadvantages of the common colorimetric signaling molecules such as low sensitivity and only qualitative/semi-quantitative results could be achieved. A novel signaling molecule dye-doped silica nanoparticles was synthesized by reverse micro-emulsion. The color of the silica nanoparticles was physically entrapped and no dye leakage was observed after surface modification. The optimal size of the dye-doped silica nanoparticles was found to be 77.25 nm for the application on the lateral flow immunoassays. The performance of the lateral flow immunoassays using silica nanoparticles outweighed all the existing tests with an extremely low detection limit (5 ng/mL). A multiplex detection lateral flow immunoassay was also developed using two different colored dye-doped silica nanoparticles at the same conjugate pad. According to the statistical pooled variance t-test, there was no statistical difference between the intensities of the test lines from the single color system and the dual color system.