Lamellar hafnium ditelluride as an ultrasensitive surface-enhanced Raman scattering platform for label-free detection of uric acid

Abstract

The development of two-dimensional (2D) transition metal dichalcogenides has been in a rapid growth phase for the utilization in surface-enhanced Raman scattering (SERS) analysis. Here, we report a promising 2D transition metal tellurides (TMTs) material, hafnium ditelluride ( HfTe 2 ), as an ultrasensitive platform for Raman identification of trace molecules, which demonstrates extraordinary SERS activity in sensitivity, uniformity, and reproducibility. The highest Raman enhancement factor of 2.32 × 10 6 is attained for a rhodamine 6G molecule through the highly efficient charge transfer process at the interface between the HfTe 2 layered structure and the adsorbed molecules. At the same time, we provide an effective route for large-scale preparation of SERS substrates in practical applications via a facile stripping strategy. Further application of the nanosheets for reliable, rapid, and label-free SERS fingerprint analysis of uric acid molecules, one of the biomarkers associated with gout disease, is performed, which indicates arresting SERS signals with the limits of detection as low as 0.1 mmol/L. The study based on this type of 2D SERS substrate not only reveals the feasibility of applying TMTs to SERS analysis, but also paves the way for nanodiagnostics, especially early marker detection.

CdSSe Nano-Flowers for Ultrasensitive Raman Detection of Antibiotics

“…Incredibly, the CdSSe NFs platform could accurately identify CIP, and ENR molecules ranged from 10 −3 M to 10 −9 M ( Figure 5 a,c). Peaks at 760, 789, 1353, 1372, and 1620 cm −1 of CIP and 638, 1248, 1395, 1465, 1536, and 1626 cm −1 of ENR could be observed clearly even when the concentration decreased to 10 −9 M [ 46 ]. Liu et al used 2D niobium ditelluride (NbTe 2 ) nanosheets as SERS substrates to realize the detection of CIP and ENR at low concentrations (about 35 ppb) [ 22 ].…”

Fast Synthesis of Au Nanoparticles on Metal–Phenolic Network for Sweat SERS Analysis

“…The biochemical assignments of these Raman bands are listed in Table 1 . It can be clearly noticed that many vibrational modes are assigned to the major components of sweat (urea, uric acid, lactic acid, and amino acid) [ 40 , 41 , 42 , 43 , 44 ], indicating the potent potential of the Au-MPN-based SERS technique for sweat identification. The SERS spectra of volunteer sweats share a basic spectral pattern; however, the obvious difference is still noticed among these 11 spectral lines.…”

“…For example, most SERS spectra exhibit a strong Raman peak at 1003 cm −1 , while the intensity of this band decreases dramatically in 5#, 9#, and 11#, revealing a low urea excretion in these three volunteers. In addition, a sharp SERS peak at 1033 cm −1 that can be ascribed to uric acid [ 41 , 44 ] is observed in the spectral line of 9#, which may be an indicator of some physiological changes.…”

Top-down produced CdSe quantum dots as an ultrasensitive SERS platform for the detection of uric acid

“…In addition, there were four acceptable CT resonance pathways between the SERS substrate and analyte: (a) the exciton resonance happens in the CdSe QDs from its VB to CB state; (b) molecular resonance occurs between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) level of the MB probe; (c) the exciton electron firstly transfers from the HOMO level of the MB molecule to a surface transition state (STS), then the electron transition from the STS to the CB edge of CdSe QDs continues to occur; and (d) the photoinduced electron transition occurs from the VB edge of the CdSe QDs to the LUMO level of MB. 36,37 In fact, the HOMO and LUMO levels of MB are À5.10 and À3.60 eV, while the VB and CB values of CdSe QDs are calculated as À4.69 and À2.31 eV, respectively. The laser wavelength is selected as 633 nm (1.96 eV) for the test, which exactly matches with the energy difference (1.09 eV) between the VB edge in the CdSe QDs and the MB LUMO level for CT resonance (the fourth way, green dotted line).…”