An Accurate and Ultrasensitive SERS Sensor with Au-Se Interface for Bioimaging and in situ Quantitation
SERS is valuable for high-sensitive and accurate bioimaging and molecule quantification. Generally for biological research, the SERS reporter molecules are connected to Au substrate for signal enhancement by Au-sulfur (Au-S) bonding. However, the extensive Au-S interface inevitably encounters with distortion by high levels of biothiols, leading to low sensitivity and false positive results. Here, we propose a kind of SERS nanoprobes with Au-selenol (Au-Se) interface for bioimaging. Compared with the Au-S SERS nanoprobes, Au-Se SERS nanoprobes show excellent stability in millimolar levels of GSH owing to higher bonding energy, and higher sensitivity due to greater chemical enhancement through Au-Se bonds. We further achieved in situ absolute quantitation of biomoleculers by ratio SERS analysis. The Au-Se SERS nanoprobes have supplied an ideal solution for accurate bioimaging and in situ quantitation.