Starch-Based Electrochemical Sensors and Biosensors: A Review

Abstract

Natural green compounds for sensor modification (binders) are challenging in electrochemistry. Starch is a carbohydrate biopolymer that has been used extensively in the development of biomaterials for the food industry due to its ability to impart textural characteristics and provide gelling or film formation. In particular, the excellent film-forming characteristics have been used for the development of new surface modifying architectures for electrodes. Here, we highlight a very comprehensive overview of the properties of interest of various types of starch in conjunction with (bio)materials in the chemical modification of sensors and biosensors. Throughout the review, we first give an introduction to the extraction, applications, and properties of starches followed by an overview of the prospects and their possible applications in electrochemical sensors and biosensors. In this context, we discuss some important characteristics of starches and different strategies of their film formation with an emphasis on their role in the development of electrochemical sensors and biosensors highlighting their main contributions to enhancing the performance of these devices and their applications in environmental and clinical samples.

Keywords: Biosensors; Modified electrodes; Natural polymer; Sensors; Starch.

Fig. 1

Basic structural motifs of amylose and amylopectin, along with the labeling of the atoms and torsion angles. Extension of the basic motifs to macromolecular structures [59]

Fig. 2

Raw starch granules observed by scanning electron microscopy: A potato; B cassava; and C rice starches. The corresponding granules under polarized light are shown in insets. D shows SEM of in situ granules in potato parenchyma cell [81] (Reprinted from Pérez et al., 2009, with permission of Elsevier)

Fig. 3

Relation of the number of articles using starch in electrochemical sensors vs. year of publication. The research was done on the Web of Science and keywords: electrochemical sensor and starch

Fig. 4

Schematic model of the methodology for producing the modified carbon paste electrodes [46] (Adapted by Azab 2019)

Fig. 5

Schematic representation for fabrication of starch nanoparticle—RGO composite molecularly imprinted polymer [121] (Reprinted from Srivastava et al., 2019 with permission of Elsevier)

Fig. 6

The schematic diagram of the experimental procedure: 1A The preparation of SS-CS/GCE; 1B The proposed mechanism for the chiral electrochemical recognition of Tyr enantiomers on SS-CS/GCE. 2 Characterization, 2A FE-SEM image of SS-CS/GCE shows a uniform surface due to the dispersion of the composite on the surface of the GCE forming a very smooth planar film; B FE-SEM image of SS-CS composite, which has a porous network structure [122] (Reprinted from Zou et al., 2019 with permission of Elsevier)

Fig. 7

Schematic illustration of Preparation of RGO-MS/GCE. A UV–Vis absorbance spectra of a RGO, b RGO-MS and c MS. B FT-IR spectra of a RGO, b RGO-MS and c MS. C AFM images, with the morphologic variation of a RGO, b RGO-MS and c MS. D Roughness bar graph, with calculated R_a (blue) and R_q (red) results. E Size distribution of a RGO, b RGO-MS, and c MS, determined by DLS. F SEM images of MS, the biopolymer film presented a homogeneous, uniform, and smooth surface. G RGO-MS, with the addition of RGO, the surface is no longer smooth, showing rough characteristics. H Present the lateral section of RGO-MS SEM images [47] (Reprinted from Orzari et al., 2018 with permission of Elsevier)

Fig. 8

Representative scheme of the preparation of activated carbon from AHS starch powder. FE-SEM images of a NPC-1, the structure with no porosity represents the inability of KOH to penetrate the surface of the carbon matrix, b NPC-2, which presents interconnected cylindrical pores due to penetration of KOH in the material network, c NPC-3, the presence of a higher number of aggregate structures without any porous morphology was observed due to the high carbonization temperature, and d the TEM image of NPC-2 [128] (Reprinted from Kasturi et al., 2021 with permission of Elsevier)