High-Performance Real-Time SERS Detection with Recyclable Ag Nanorods@HfO2Substrates.
Ag nanorods coated with an ultrathin HfO2shell (Ag NRs@HfO2) were prepared for the synthesis of a versatile, robust, and easily recyclable surface-enhanced Raman scattering (SERS) substrate. This substrate maximizes the high melting point of the HfO2shell and thus ensures the excellent plasmonic efficiency of Ag NRs. Therefore, it possesses extraordinary thermal stability and SERS activity, which could act as a reusable and cost-effective SERS detector. After SERS detection, the regeneration of Ag NRs@HfO2was achieved by annealing the substrate within several seconds. This procedure led to the thermal release of adsorbed molecules and resulted in a refreshed substrate for subsequent measurements. The composite substrate maintained its SERS efficiency well during multiple "detection-heating" cycles, hence demonstrating the stability and recyclability of Ag NRs@HfO2. Furthermore, in addition to revealing the feasibility of SERS sensing in liquids, Ag NRs@HfO2also provided continuous real-time monitoring of vapor-phase samples at ultralow concentrations. This work provides a robust and renewable SERS sensor with advantages of high sensitivity, stability, cost effectiveness, and easy operation, which can be implemented for both aqueous and gaseous analyte detection and is thus an intriguing candidate for practical applications in environmental, industrial, and homeland security sensing fields.
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, P. R. China.
Lingwei
L
Ma
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, P. R. China.
Hui
H
Wu
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, P. R. China.
Yu
Y
Huang
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, P. R. China.
Sumeng
S
Zou
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, P. R. China.
Jianghao
J
Li
Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University , Beijing 100084, P. R. China.
Zhengjun
Z
Zhang
SERS; aqueous and vapor-phase molecule sensing; core−shell structure; recyclability; thermal stability