An aggregated perylene-based broad-spectrum, efficient and label-free quencher for multiplexed fluorescent bioassays

Fluorescent sensing systems based on the quenching of fluorophores have found wide applications in bioassays. An efficient quencher will endow the sensing system a high sensitivity. The frequently used quenchers are based on organic molecules or nanomaterials, which usually need tedious synthesizing and modifying steps, and exhibit different quenching efficiencies to different fluorophores. In this work, we for the first time report that aggregated perylene derivative can serve as a broad-spectrum and label-free quencher that is able to efficiently quench a variety of fluorophores, such as green, red and far red dyes labeled on DNA. By choosing nucleases as model biomolecules, such a broad-spectrum quencher was then employed to construct a multiplexed bioassay platform through a label-free manner. Due to the high quenching efficiency of the aggregated perylene, the proposed platform could detect nuclease with high sensitivity, with a detection limit of 0.03U/mL for EcoRV, and 0.05U/mL for EcoRI. The perylene quencher does not affect the activity of nuclease, which makes it possible to design post-addition type bioassay platform. Moreover, the proposed platform allows simultaneous and multicolor analysis of nucleases in homogeneous solution, demonstrating its value of potential application in rapid screening of multiple bio-targets.