Behind the Optimization of the Sensor Film: Bioconjugation of Triangular Gold Nanoparticles with Hemoproteins for Sensitivity Enhancement of Enzymatic Biosensors

Abstract

Electrochemical biosensors are widely used in a multitude of applications, such as medical, nutrition, research, among other fields. These sensors have been historically used and have not undergone many changes in terms of the involved electrochemical processes. In this work, we propose a new approach on the immobilization and enhancement of the electrochemical properties of the sensing layers through the control and bioconjugation of hemoproteins (hemoglobin, myoglobin, and cytochrome C) on anisotropic gold nanoparticles (gold nanotriangles (AuNTs)). The hemeproteins and the AuNTs are mixed in a solution, resulting in stable bioconjugates that are deposited onto the electrode surface to obtain the biosensors. All the systems proposed herein exhibited direct well-defined redox responses, highlighting the key role of the AuNTs acting as mediators of such electron transfers. Several protein layers surrounding the AuNTs are electroactive, as demonstrated from the charge measured by cyclic voltammetry. The retention of the stability of the hemeproteins once they are part of the bioconjugates is evidenced towards the electrocatalytic reduction of hydrogen peroxide, oxygen, and nitrite. The parameters obtained for the proposed biosensors are similar or even lower than those previously reported for similar systems based on nanomaterials, and they exhibit attractive properties that make them potential candidates for the latest developments in the field of sensing devices.

A Study on the Mechanism and Properties of a Self-Powered H2O2 Electrochemical Sensor Based on a Fuel Cell Configuration with FePc and Graphene Cathode Catalyst Materials

“…The electrodes are therefore modified with the catalyst to improve the thermodynamics and kinetics of the electrode reactions as well as the analytical characteristics of the respective sensors, such as natural enzymes [ 3 , 8 , 19 , 20 ], non-enzymatic electrocatalysts including metal nanostructures [ 21 , 22 , 23 ], carbonaceous nanomaterials, enzyme mimetics, and nanozymes such as metallocomplexes and Prussian blue [ 6 , 7 , 8 , 24 , 25 , 26 , 27 ]. Of the aforementioned materials, enzymatic catalysts have advantages in terms of specificity and high catalytic activity, which are determined by the properties of the enzymes.…”

An Overview of Environmental Catalysis Mediated by Hydrogen Peroxide

“…In order to ensure an optimized electron transfer, these proteins are often immobilized on highly conductive materials, both organic and inorganic, with a large surface area [248]. Interesting examples of these materials that also find application in the bio-medical sector are gold nanoparticles [249][250][251], nanometric metal oxides [252,253], metal nanoparticle-MOF [254][255][256][257], carbon nanotube-MOF [258] and metal nanoparticle-polymers [259,260].…”

Biohybrid materials comprising an artificial peroxidase and differently shaped gold nanoparticles

“…24–26 Further, the immobilization of redox-active enzymes on gold-based materials is of great interest in the field of electrochemical biosensors, as AuNMs may act as mediators and facilitate electron exchanges between the electrode and the biomolecular component. 27–30 Within this topic, the introduction of shape anisotropy at the nanoscale has emerged as a potent way to access new properties and functionalities, enabling the exploration of complex nanomaterials across a wide range of applications. 31 Differently shaped AuNMs, like rods (AuNRs), triangular nanoprisms (AuNTs), and branched multipods like nanostars, nanowires or nanocubes, have gained interest beyond spherical gold-nanoparticles (AuNPs).…”

“…16,18,32–35 In particular, the organization and patterning of inorganic nanoparticles into surface-deposited well-ordered nanostructures are of increasing interest in the development of biosensing devices based on redox-active enzymes. 28–30,36,37 In this scenario, the combination of the unique features of anisotropic AuNMs with artificial metalloenzymes (ArMs) may further broaden the array of functional nanomaterials useful for the assembly of chemical, optical, and electronic devices. Diverse and powerful strategies have been developed for the design of ArMs tailored ad hoc , endowed with a reduced size, and able to perform natural and unnatural reactions.…”