96-Well Plasmonic Sensing with Nanohole Arrays

A multiwell plasmonic reader was designed and validated for higher throughput analysis of biological interactions with a platform of the same size as standard 96-well plates, While the plasmonic sensor can be read with standard 96-well plate readers, a custom 96-well plate reader was designed to analyze nanohole arrays at high incident angles required for higher sensitivity. Gold nanohole arrays were manufactured on a 4 in. glass wafer using a photolithographic process. In comparison to single channel measurements with nanohole arrays fabricated with nanosphere lithography, the nanohole array sensors greatly enhanced the signal-to-noise ratio of the plasmonic signal and precision of the measurements with the multiwell plate system. As proof of concept, the detection of IgG in the low nanomolar range was achieved with the multiwell plate reader. The multiwell plasmonic plate reader was also applied to the screening of several prostate specific (PSA) antibodies for secondary detection of PSA and for the analysis of an anticancer drug through a competitive assay between methotrexate (MTX) and folic acid Au nanoparticle (FaNP) for human dihydrofolate reductase (hDHFR). The multiwell plasmonic reader based on nanohole array technology offers the rapid, versatile, sensitive, and simple high throughput detection of biomolecules.