Microwaves + Nanoparticles = Ultrafast, Ultrasensitive Assays

This work, conducted by Kadir Aslan, Ph.D., and Chris Geddes, Ph.D., is reported in the journal Analytical Chemistry.

The new assay technology relies on two physical processes. Metal-enhanced fluorescence is a recently observed phenomenon that boosts the intensity of a fluorescent signal through the interaction of a weakly fluorescent probe with metal nanoparticles. Low power microwave radiation has been gaining use as a means of accelerating a variety of chemical reactions. Combining the two into a single, easy to use format resulted in an assay system that was 90 times faster than a conventional protein binding system with a 10-fold boost in sensitivity.

Constructing the assay system involves coating a glass slide with a thin film of silver nanoparticles, and then adding the sample to be assayed. Proteins in the sample will stick to the silver layer. Next, a fluorescently labeled detection reagent – a molecule designed to bind to the specific protein of interest – is added and the slide is then heated with microwaves for 20 seconds. The slide is then washed to remove unreacted detection reagent and then surveyed for any fluorescent signal using a standard spectrophotometer.

This work is detailed in a paper titled, “Microwave-accelerated metal-enhanced fluorescence: platform technology for ultrafast and ultrabright assays.” An abstract is available through PubMed.

Source: National Cancer Institute