Acridine-based dyes as high-performance near-infrared Raman reporter molecules for cell imaging.

A surface-enhanced Raman scattering (SERS) nanoprobe has been proven to be a promising tool for near-infrared (NIR) biomedical imaging and diagnosis because of its high sensitivity and selectivity. However, the development of NIR SERS reporters has been a bottleneck impeding the preparation of ultrasensitive SERS probes. Herein, we report the design and synthesis of a series of SERS reporters in the NIR region based on 10-methylacridine (AD). The AD nanotags (gold nanostar-AD molecules-BSA, AuNS-AD-BSA) exhibit appreciable SERS signals and can be detected at as low as the sub-picomole level. The results of in vitro imaging experiments show that it can be used in live-cell delineation.