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 ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>HfTe</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> ), 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 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:mn>2.32</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mn>6</mml:mn> </mml:msup> </mml:mrow> </mml:math> is attained for a rhodamine 6G molecule through the highly efficient charge transfer process at the interface between the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m3"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>HfTe</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> 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.