**Acknowledgements**

*Assorted Dimensional Reconfigurable Materials*

quartz and silicon.

**6. Conclusion**

cially available SERS substrates.

substrates relatively quickly and easily.

are characterized by obtaining enhancement of 105

responsible for the observed enhancement of SERS [103].

difficult, and not effective for areas larger than 1 mm<sup>2</sup>

Taking into account all the requirements for an ideal SERS substrate, which are mentioned above, the anodic oxide-based nanocomposites as SERS substrate can become an efficient and popular product. Nowadays, the possibility of applying this material as a highly active SERS substrate is in the research phase, and the results are very promising. The prospective role of advanced anodic oxide based nanocom-

• No fluorescence and very low background, similar to the values recorded for

• The production of anodic oxides is relatively easy and fast process, so the cost of such production would be significantly lower than the cost of now commer-

• The structures obtained by anodization are characterized by a large specific surface area, repeatability, and the ability to control geometric parameters by means of manufacturing process parameters (e.g., anodization potential or process temperature), which ensure the repeatability of SERS analyses.

• It is possible to increase the production scale of anodic oxide-based SERS

Despite the undoubted advantages and potentially large possibilities of the widespread use of SERS spectroscopy in many field, its progress has been hampered by the inability of scientists and industry to produce SERS substrates with high sensitivity, stability, and repeatability. Currently commercially available SERS substrates

several days and 6 months. The above limitations appear due to the relatively small control over the morphology of substrate structures at the nanoscale, which are

It is important to have the reproducible and homogeneous distribution of nanostructures over the entire surface of the SERS substrate, while obtaining large areas that meet these conditions. The next step is to find technology to transfer these results from the laboratory to the industrial scale providing some technological problems. The use of conventional nanostructures in fabrication methods becomes less attractive because they are relatively expensive, time-consuming,

oxide template for the production of nanostructures, despite promising results at the nanoscale, is fraught with many problems arising when attempting to increase the scale of production, including a complicated, multi-stage, and difficult process for producing ultrathin membranes; ordering structures only in the domain area; and difficulties in obtaining repetitive systems of nanostructure. On the other hand, the outstanding array structure made by AAO template-assisted method has a promising practical application in SERS field, so this direction will be probably developed in the future. Also using the ATO for SERS substrate production seems to be a promising solution: the possibility of combining relatively ordered nanopores/ nanotubes with its photocatalytic properties to utilize SERS substrates self-cleaning effect gives a big perspective of application on that material. In the future probably the composite SERS substrates based on AAO/ATO and Ag or Au will be commer-

–107

and durability between

. The use of anodic aluminum

posites as SERS substrate can be attributed to the following features:

**72**

cially available.

This work was financed by the National Centre for Research and Development (Poland) under program LIDER IX (Nr LIDER/50/0199/L-9/17/NCBR/2018). M. Michalska-Domańska cordially acknowledges financial support from the Polish Ministry of Science and Higher Education (Scholarship for Young, Outstanding Researchers 2016–2019, agreement no. 1013/E-410/STYP/11/2016). The author thanks Dr. P. Nyga for the help in finding information about commercially available SERS substrates.
