Rapid detection method and portable device based on the photothermal effect of gold nanoparticles.

Gold nanoparticle (GNP)-labeled immunochromatography test strip (ICTS) has been widely used in different fields, but its sensitivity still require further improvement. In this work, a rapid and quantitative test strip detection method based on the photothermal effect of GNPs was established using a temperature sensor. A portable sensor device was fabricated based on the above method, and the main operating parameters were optimized. Three types of analyte models (cells, macromolecules, and small molecules) were chosen to evaluate the application of the sensor device using the commercial ICTS. The detection limit is at least 1 order of magnitude lower than that of the traditional visual detection ICTS. The other strip type of dot immunogold filtration test was adopted to further improve the sensitivity. The sensitivity of the sensor detection method was similar to that of the infrared camera method, and the proposed sensor device has obvious advantage of low-cost, as well as the usage of a small portable instrument, ease of use and rapid test. The portable sensor device based on the photothermal effect of GNPs can be used as a new and promising device for simple, quantitative, rapid, and on-site screening of analyte by ICTS.