Multiplex Surface-Enhanced Raman Scattering Identification and Quantification of Urine Metabolites in Patient Samples within 30 Minutes.

Successful translation of laboratory-based surface-enhanced Raman scattering (SERS) platforms to clinical applications requires multiplex and ultratrace detection of small metabolites from a complex biofluid. However, these metabolites exhibit low Raman scattering cross-sections and do not possess specific affinity to plasmonic nanoparticle surfaces, significantly increasing the challenge of detecting them at low concentrations. Herein, a 'confine-and-capture' approach is demonstrated for multiplex detection of two families of urine metabolites correlated with miscarriage risks, 5β-pregnane-3α,20α-diol-3α-glucuronide and tetrahydrocortisone. To enhance SERS signals by 1012-fold, specific nanoscale surface chemistry is used for targeted metabolite capture from a complex urine matrix prior to confining them on a superhydrophobic SERS platform. Applying chemometrics, including principal component analysis and partial least square regression, enables conversion of molecular fingerprint information into quantifiable readouts. The whole screening procedure requires only 30 minutes, including urine pretreatment, sample drying on the SPHB-mirror platform, SERS measurements and chemometric analyses. These readouts correlate well with the pregnancy outcomes in a case-control study of 40 patients presenting threatened miscarriage symptoms.