Nanostructured Electrochemical Biosensors for Label-Free Detection of Water- and Food-Borne Pathogens

Abstract

The emergence of nanostructured materials has opened new horizons in the development of next generation biosensors. Being able to control the design of the electrode interface at the nanoscale combined with the intrinsic characteristics of the nanomaterials engenders novel biosensing platforms with improved capabilities. The purpose of this review is to provide a comprehensive and critical overview of the latest trends in emerging nanostructured electrochemical biosensors. A detailed description and discussion of recent approaches to construct label-free electrochemical nanostructured electrodes is given with special focus on pathogen detection for environmental monitoring and food safety. This includes the use of nanoscale materials such as nanotubes, nanowires, nanoparticles, and nanosheets as well as porous nanostructured materials including nanoporous anodic alumina, mesoporous silica, porous silicon, and polystyrene nanochannels. These platforms may pave the way toward the development of point-of-care portable electronic devices for applications ranging from environmental analysis to biomedical diagnostics.

Trimetallic Nanoparticles: Greener Synthesis and Their Applications

“…The preparation of graphene nanocomposites by engaging appropriate composite nanostructures that rendered an excellent synergetic effect between the constituent components and provided a good anchoring site for the insertion and/or stabilization of metal/metal oxide NPs is still a main challenge. While maintaining the exceptional features of each composite in the synthesis of good homogeneous nanocomposites, the layer-by-layer (LBL) deposition technique fulfils all these requirements [ 116 , 117 , 118 ]. One of the effective and key characteristics of LBL assembly for the fabrication of differently layered nanocomposites is the functionalization of nanomaterials; these nano-based biosensors could render promising nanoplatforms for the advancement of other biosensors [ 118 ].…”

Porous Alumina Membrane-Based Electrochemical Biosensor for Protein Biomarker Detection in Chronic Wounds

“…The uniformity and homogeneity of NAA structures contribute to enhance their reproducibility, leading to sensing platforms able to provide accurate and reliable sensing results. NAA also has high chemical, thermal and mechanical stability, and excellent biocompatibility, overcoming some of the limitations encountered by other types of porous materials (Rajeev et al, 2018;Reta et al, 2018). An additional advantage of NAA worth to harness when developing biosensors relates to the chemical properties of NAA, particularly the large amount of hydroxyl groups present on its porous surface, which allow facile biofunctionalization.…”

“…The partial or complete blockage of NAA nanochannels due to analyte specific binding to capture probes immobilized within the pores has been used as a sensing strategy for direct and labelfree electrochemical detection of various biomolecules (Vlassiouk et al, 2005;Koh et al, 2007;Nguyen et al, 2009Nguyen et al, , 2012Merkoçi, 2010, 2011;de la Escosura-Muñiz et al, 2013;Espinoza-Castañeda et al, 2015;Tang et al, 2016;Reta et al, 2018). A blocking event impedes the diffusion of an electroactive species added in solution to the electrode surface which is measured as a reduction in oxidation current.…”

In Situ Determination of pH at Nanostructured Carbon Electrodes Using IR Spectroscopy

“…Carbon nanostructured electrodes are ubiquitous in electrochemistry, used as electrocatalyst supports [1], as energy storage electrodes with a large surface area, found in supercapacitors [2], as redox flow batteries [3], and in sensing and electroanalysis [4][5][6]. The biocompatible nature of some nanocarbons, such as carbon nanotubes, has led to their use in the modification of electrodes for biological sensing [7], the detection of neurotransmitters [8], the stimulation of nervous tissues [9], pathogen detection [10], and interfacing with enzymes [11]. However, in many key redox reactions of biological interest, such as the oxidation of dopamine and other quinones, the proton-coupled nature of the electron transfer can result in a local pH change [12].…”