Synergistic SERS Enhancement in GaN‐Ag Hybrid System toward Label‐Free and Multiplexed Detection of Antibiotics in Aqueous Solutions

Abstract

Noble metal-based surface-enhanced Raman spectroscopy (SERS) has enabled the simple and efficient detection of trace-amount molecules via significant electromagnetic enhancements at hot spots. However, the small Raman cross-section of various analytes forces the use of a Raman reporter for specific surface functionalization, which is time-consuming and limited to low-molecular-weight analytes. To tackle these issues, a hybrid SERS substrate utilizing Ag as plasmonic structures and GaN as charge transfer enhancement centers is presented. By the conformal printing of Ag nanowires onto GaN nanopillars, a highly sensitive SERS substrate with excellent uniformity can be fabricated. As a result, remarkable SERS performance with a substrate enhancement factor of 1.4 × 10 11 at 10 fM for rhodamine 6G molecules with minimal spot variations can be realized. Furthermore, quantification and multiplexing capabilities without surface treatments are demonstrated by detecting harmful antibiotics in aqueous solutions. This work paves the way for the development of a highly sensitive SERS substrate by constructing complex metal-semiconductor architectures.

Light-to-Hydrogen Improvement Based on Three-Factored Au@CeO2/Gr Hierarchical Photocatalysts

“…Surface plasmon resonance (SPR) has been extensively employed for light-harvesting and conversion . Gold (Au) is considered a very promising SPR host because it offers tunable plasmon resonances in visible-light frequencies and excellent stability under harsh catalytic conditions. − The energy stored in the SPR excitation may dissipate both radiatively and nonradiatively.…”

A portable SERS sensing platform for the multiplex identification and quantification of pesticide residues on plant leaves

“…SERS is an efficient and universal analysis technology with unique molecular fingerprint information. Due to its rapid and nondestructive detection characteristics, SERS technology has been widely used in environmental monitoring, 9 food safety, 10,11 chemical analysis and other fields. 12–14 In general, the SERS enhancement mechanism mainly includes the electromagnetic enhancement mechanism (EM) and chemical enhancement mechanism (CM).…”

“…15,16 Consequently, an effective way to enhance the sensitivity of SERS is to fully combine the EM and CM mechanisms before the design of the substrate. For example, Lee et al 11 proposed a GaN/Ag hybrid SERS substrate, which exhibits superior SERS sensitivity for the detection of rhodamine 6G. Yang et al 17 reported an Au/W 18 O 49 heterostructure to realize quantitative and qualitative double detection with SERS monitoring and fluorescence sensing.…”

Synergistic SERS enhancement and in situ monitoring of photocatalytic reactions in a plasmonic metal/ferroelectric hybrid system by the light-induced pyroelectric effect

“…Based on a simple nanofiber preparation technology, namely electrospinning, an electrospun pyroelectric-modulated BiFeO 3 layer combined with an electron/heat conduction layer of CNFs may be the optimal choice to fabricate an efficient light-induced pyroelectric layer. 21,22 In addition, Ag NWs are one of the most promising SERS substrates due to their peculiar geometry with a non-circular cross-section and sharp tips, which allows for the efficient enrichment of the local electromagnetic field. 23–25 Owing to the emergence of hot spots among uniformly dispersed Ag NWs on BiFeO 3 /carbon nanofiber surfaces, hybrid SERS substrates will exhibit excellent light absorption, outstanding stability and tunable electric fields.…”