Forster resonance energy transfer (FRET) reporters are often used in tests to show if specific genetic material is present. In these tests, certain enzymes called nucleases cut the FRET reporters, causing them to emit light. However, making these FRET reporters involves using a dye/quencher pair and purifying them, which makes the FRET reporters expensive.

Researchers at UT Austin introduced a cheaper alternative: silver nanocluster reporters. These reporters don’t rely on the FRET process to turn on and off. Instead, they rely on cluster transformation process that changes color when they’re cut by nucleases. This innovative reporter is named Subak (meaning watermelon in Korean) after its unique fluorescent color changes from green to red upon digestion. “We found that after being cut, these reporters emit light with a very different color, which allows us to do ratio metric sensing that is not typically available in the traditional FRET reporters” (Hong, Walker, Luong, et al., 2024). 

This was recently published in Nature Nanotechnology which featured both Dr. Tim Yeh, Associate Professor in Biomedical Engineering and Texas Materials Institute at UT Austin, and Biomedical Engineering Ph.D. student, Soonwoo Hong. They collaborated with Dr. Jennifer Brodbelt’s group in the Department of Chemistry, in order to discover that the change in color happens because the size of the silver nanoclusters changes when their DNA templates are cut by nucleases. This suggests that these silver nanoclusters can be useful for detecting enzyme activities and help us understand how enzymes interact with nanomaterials made of metal and DNA.

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