Rapid SERS assay for determination of the opioid fentanyl using silver-coated sharply branched gold nanostars.

Abstract

Ahigh-throughput surface-enhanced Raman scattering (SERS)-sensing platform is presentedfor FNT detection in human urine without any sample preparation. The sensing platform is based on plasmonics-active silver-coated sharply branched gold nanostars (SGNS). The effect of silver thickness was investigated experimentally and theoretically, and the results indicated that SERS enhancement was maximum at an optimum silver thickness of 45nm on the sharply spiked SGNS. The proposed high-throughput SERS platform exhibited ultrahigh sensitivity and excellent enhancement uniformity for a model analyte, i.e., crystal violet. Moreover, the SERS-sensing platform demonstrated good sensitivity of FNT spiked in human urine samples with two differential linear responseranges of2 to 0.2µg/mL and 0.1µg/mL to 100pg/mL,respectively, with a detection limit as low as 10.02pg/mL. The spiked human urine samples show satisfactory recovery values from 92.5 to 102% with relative standard deviations (RSD) of less than 10%. In summary, the high-throughput performance of the proposed microplate-based SERS platform demonstrated great potential for rapid low-cost SERS-based sensing applications.