A SERS-Assisted 3D Barcode Chip for High-Throughput Biosensing.

A surface enhanced Raman scattering (SERS)-assisted 3D barcode chip has been developed for high-throughput biosensing. The 3D barcode is realized through joint 2D spatial encoding with the Raman spectroscopic encoding, which stores the SERS fingerprint information in the format of a 2D array. Here, the concept of SERS-assisted 3D barcode is demonstrated through multiplex immunoassay, where simultaneous detection of multiple targets in different samples has been achieved using a microfluidic platform. First, multiple proteins in different samples are spatially separated using a microfluidic patterned antibody barcode substrate, forming a 2D hybridization array. Then the SERS probes are used to identify and quantify the proteins. As different SERS probes are labeled with different Raman reporters, they could be employed as "SERS tags" to incorporate spectroscopic information into the 3D barcode. In this 3D barcode, the 2D spatial information helps to differentiate the samples and targets while the SERS information allows quantitative multiplex detection. It is found that the SERS-assisted 3D barcode chip can not only accomplish one-step multiplex detection within 30 min but also achieve an ultrasensitivity down to 10 fg mL(-1) (≈70 aM), which is expected to provide a promising tool for high-throughput biomedical applications.