Timeshare Surface-Enhanced Raman Scattering Platform with Sensitive and Quantitative Mode

• • The timeshare SERS platform resolves the sensitivity–quantification trade-off by dynamically controlling inter-nanosphere distance via hydrogel volume change, enabling on-demand switching between quantitative and sensitive modes without altering analyte spatial distribution. • • In quantitative mode (no hottest spots), the platform provides strong quantification capability, essential for accurate concentration determination in trace analysis; in sensitive mode (with substantial hottest spots), it achieves ultrahigh sensitivity, enabling detection of various analyte molecules at ultralow levels. • • The platform's design—monolayer gold nanosphere film on elastic hydrogel—allows reversible formation and extinction of SERS hottest spots, a critical advance over static SERS substrates that cannot reconcile signal amplification with molecular counting. • • This technology addresses urgent needs in analytical chemistry, environmental science, food safety, and biomedical fields where both quantitative and sensitive detection of trace analytes is required, potentially enabling reliable quantification without sacrificing single-molecule sensitivity.