Facile in situ synthesis of core–shell MOF@Ag nanoparticle composites on screen-printed electrodes for ultrasensitive SERS detection of polycyclic aromatic hydrocarbons

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2019, Vol.7 (23), p.14108-14117
• Main Authors: Li, Dan, Cao, Xiukai, Zhang, Qinmei, Ren, Xingang, Jiang, Lei, Li, Dawei, Deng, Wei, Liu, Haitao
• Format: Article
• Language: English
• Subjects: Composite materials; Copper; Core-shell structure; Detection limits; Electrodeposition; Electrodes; Fabrication; Metal-organic frameworks; Morphology; Nanoparticles; Polycyclic aromatic hydrocarbons; Quantitative analysis; Raman spectra; Selectivity; Sensitivity; Sensitivity enhancement; Silver; Substrates
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C9TA03690C

This paper reports the fabrication of a highly sensitive and reusable substrate for surface-enhanced Raman scattering (SERS) analysis. Core–shell metal–organic framework (MOF; HKUST-1)@Ag nanoparticles (NPs) are prepared on a screen-printed carbon electrode (SPCE) via in situ electrodeposition. The morphology and Ag coverage of core–shell structures can be easily controlled by electrodeposition potential and time without substrate motion. The HKUST-1(Cu)@Ag composites combine abundant SERS “hot spots” among the high-density Ag NPs and the excellent adsorption performance of the MOF, resulting in effective pre-concentration of analytes in close proximity to these “hot spots” and enhancement of SERS sensitivity. The optimized polyhedral HKUST-1@Ag structures exhibit high SERS activity for detecting 4-aminothiophenol at a concentration as low as 5 × 10 −10 M. More importantly, the polyhedral HKUST-1@Ag composites provide high sensitivity for detection of polycyclic aromatic hydrocarbons (PAHs) while preserving the cyclability and selectivity required for reliable quantitative analysis. The method is effective over a wide range of PAH concentrations (0.5 nM to 0.5 M), with detection limits as low as hundreds of pM. This study offers a new method to tailor the structure of MOF-based SERS substrates for on-site screening or point-of-care applications.