"One-Pot" Readout Cyano-Programmable SERS-Encoded Platform Enables Ultrasensitive and Interference-Free Detection of...

Surface-enhanced Raman spectroscopy (SERS) detection platforms with high signal-to-noise ratio in the "biological-silent" region (1800-2800 cm^-1) are presently being developed for sensing and imaging applications, overcoming the limitations of traditional SERS studies in the "fingerprint" region. Herein, a series of cyano-programmable Raman reporters (RRs) operating in the "biological-silent" region were designed based on 4-mercaptobenzonitrile derivatives and then embedded in core-shell Au@Ag nanostars using a "bottom-up" strategy to provide SERS enhancement and encapsulation protection. The approach enabled the "one-pot" readout interference-free detection of multiple bioamines (histamine, tyramine, and β-phenethylamine) based on aptamer-driven magnetic-induced technology. Three cyano-encoded SERS tags resulted in separate SERS signals for histamine, tyramine, and β-phenethylamine at 2220, 2251, and 2150 cm^-1, respectively. A target-specific aptamer-complementary DNA competitive binding strategy allowed the formation of microscale core-satellite assemblies between Fe₃O₄-based magnetic beads and the SERS tags, enabling multiple SERS signals to be observed simultaneously under a 785 nm laser excitation laser. The LODs for detection of the three bioamines were 0.61 × 10^-5, 2.67 × 10^-5, and 1.78 × 10^-5 mg L^-1, respectively. The SERS-encoded platform utilizing programmable reporters provides a fast and sensitive approach for the simultaneous detection of multiple biomarkers, paving the way for routine SERS analyses of multiple analytes in complex matrices.