Ultrasensitive opto-microfluidic immunosensor integrating gold nanoparticle-enhanced chemiluminescence and highly stable organic photodetector

The expensive fabrication of current opto-microfluidic sensors is a barrier to the successful adoption of these devices in point-of-care testing. This work reports a simple inexpensive opto-microfluidic device incorporating a poly(dimethylsiloxane)-glass hybrid microfluidic chip modified with gold nanoparticles and a high-detectivity, high-stability organic photodetector. The enhancing effect of the gold nanoparticles on horseradish peroxidase-luminol-H2O2 chemiluminescence was exploited in rapid single-analyte immunoassays. The limit of detection for 17-beta estradiol was 2.5 pg/ml, which is similar to 200 times more sensitive than previously reported chemiluminescent immunosensors employing other organic photodetectors. Detection was also demonstrated in complex media, including natural water and blood serum. (C) 2014 Society of Photo-Optical Instrumentation Engineers (SPIE)