Recent Advances on Diatom-Based Biosensors

Abstract

Porous materials showing some useful transducing features, i.e., any changes in their physical or chemical properties as a consequence of molecular interaction, are very attractive in the realization of sensors and biosensors. Diatom frustules have been gaining support for biosensors since they are made of nanostructured amorphous silica, but do not require any nano-fabrication step; their surface can be easily functionalized and customized for specific application; diatom frustules are photoluminescent, and they can be found in almost every pond of water on the Earth, thus assuring large and low-cost availability. In this review, the most recent advances in diatom-based biosensors are reported, and a perspective view on future developments is given.

Keywords: biosensors; diatoms; nanotechnology; porous materials.

Figure 1

Scanning electron microscope images of the Coscinodiscus wailesii diatom valves at different magnifications (Images courtesy of Prof. M. De Stefano, University of Campania “Vanvitelli”, Italy).

Figure 2

Different shapes, sizes, and morphologies of diatom frustules in an optical image (125× magnification). Frustule dimensions could range from few microns up to a millimeter (Copyright to http://golubcollection.berkeley.edu/diatoms/modern.html).

Figure 3

Schematic representation of Ag NPs’ growth on a diatom surface (a) FE-SEM top-view images of diatom (b) and in situ synthesized Ag NPs on diatom surface; (c) i–iii various magnifications of the NP-populated diatom. Reprinted with permission from [40]. Copyright 2019 American Chemical Society.

Figure 4

Schematic of quantification of the signal from imaged diatom frustules. Reprinted with permission from [52]. Copyright 2019 Elsevier.