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Anodized Nanoporous Gold as an ultra-sensitive sensor-substrate for SERS

AnodizationChemical de-alloyingelectro-catalystNanoporous goldSERS


The invention is an innovative sensor-substrate for SERS (Surface Enhanced Raman Spectroscopy) application that exhibits a higher SERS activity being able to reveal molecules in extremely low concentration. It is constituted by anodized nanoporous gold (A-NPG) prepared by de-alloying of amorphous ribbons to get nanoporous gold (NPG) followed by anodization, forming more active and tiny features on the surface.

Technical features

SERS substrates currently on the market are assembled on a handling plate material of larger dimension respect to the active area, that limits their versatility of use. Furthermore, such devices are disposable and with a limited detection limit.

A-NPGs are self-standing, mechanically stable and flexible; this makes the integration of the substrate into a handling plate unnecessary, widening their application in different operative conditions: their ribbon shape provides an extremely practical use for solution measurements, at air after incubation and in the cuvette. The substrates provide a strongly enhanced SERS signal with a detection limit of 10-16M and taking advantage of the mechanical stability can be incorporated in sensors and small devices. An unique hallmarks is the possibility to reuse the substrate several times, keeping its sensitivity unchanged after washing in a proper solution and rinsing in deionized water, something not ever foreseen by the substrates on the market.

Possible Applications

  • Ultra-sensitive sensor-substrate for SERS;
  • Possible integration as a part of sensor or sensor itself;
  • Electrode for electro-catalysis.


  • Strongly enhanced SERS signal;
  • Detection limit of 10-16;
  • Self-standing, mechanically stable and flexible;
  • No need of a handling plate;
  • Different operative conditions: in solution, at air, in cuvette;
  • It can be re-used several times keeping its sensitivity unchanged after washing procedure.