Development of a simple bioelectrode for the electrochemical detection of hydrogen peroxide using Pichia pastoris catalase immobilized on gold nanoparticle nanotubes and polythiophene hybrid

Abstract

In this paper, a simple and innovative electrochemical hydrogen peroxide biosensor has been proposed using catalase (CATpp) derived from Pichia pastoris as bioelectrocatalyst. The model biocomponent was immobilized on gold nanoparticle nanotubes (AuNPNTs) and polythiophene composite using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide and N-hydroxysuccinimide (EDC-NHS) coupling reagent. In this present work, we have successfully synthesized gold nanoparticles (AuNPs) by ultrasonic irradiation. The tubular gold nanostructures containing coalesced AuNPs were obtained by sacrificial template synthesis. The assembly of AuNPNTs onto the graphite (Gr) electrode was achieved via S-Au chemisorption. The latter was pre-coated with electropolymerized thiophene (PTh) to enable S groups to bind AuNPNTs. The combination of AuNPNTs-PTh, i.e., an inorganic-organic hybrid, provides a stable enzyme immobilization platform. The physical morphology of the fabricated biosensor Gr/PTh/AuNPNTs/EDC-NHS/CATpp was investigated using scanning electron microscopy and energy-dispersive microscopy. The analytical performance of the bioelectrode was examined using cyclic voltammetry, differential pulse voltammetry and chronoamperometry. Operational parameters such as working potential, pH, and thermal stability of the modified electrode were examined. The beneficial analytical characteristics of the proposed electrode were demonstrated. Our results indicate that the Gr/PTh/AuNPNTs/EDC-NHS/CATpp bioelectrode exhibits a wide linear range from 0.05 mM to 18.5 mM of H2O2, fast response time of 7 s, excellent sensitivity of 26.2 mA mM(-1) cm(-2), good detection limit of 0.12 μM and good Michaelis-Menten constant of 1.4 mM. In addition, the bioelectrode displayed good repeatability, high stability and acceptable reproducibility, which can be attributed to the AuNPNTs-PTh composite that provides a biocompatible micro-environment.

Improving Functional Behavior of MCM‐41 by Encapsulating MnO2 Nanorods towards Simultaneous Determination of Purine Bases in DNA Samples

“…Electrochemical impedance studies cater on the understanding of surface property changes of the modified electrodes. Incorporation of MnO 2 nanorods on MCM-41 enhances its conductivity [38][39][40][41]. Figure 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 decrease in peak to peak separation (160 mV) is observed in the case of GCE/MnO 2 (curve b) which justifies speeded electron transfer kinetics at GCE/MnO 2 as a result of improved electrical conductivity due to MnO 2 nanorods.…”

“…However, the results for MnO 2 @MCM-41 showed a midway response between that of only MCM-41 and MnO 2 . The higher frequency region encompassing the semicircular portion of the Nyquist plot, relates to the electron transfer process whereas the linear portion in the lower frequency accounts for the diffusion process [39,40]. Incorporation of MnO 2 nanorods on MCM-41 enhances its conductivity [38][39][40][41].…”

A novel bioassay based gold nanoribbon biosensor to aid the preclinical evaluation of anticancer properties

“…are some of the examples of nanomaterials that are known to increase the performance of biosensors in terms of the selectivity, sensitivity and long term stability. We have reported gold nanoparticle nanotubes (AuNPNTs) employing an alumina membrane as a template 29 and Au nanotubes synthesized using b-diphenylalanine (b-FF) as a sacricial template. 20,21 Apart from this, they are also used widely in the elds of fuel cells, batteries and super capacitors.…”

Películas nanoestructuradas de polímeroshiperramificados como plantillas para laformación de estructuras metálicas

“…[10]. La detección electroquímica de H 2 O 2 tiene sus ventajas sobre otras técnicas debido a su alta sensibilidad, selectividad, e inmediata respuesta, por ello, los métodos electroquímicos han sido ampliamente desarrollados para la detección de H 2 O 2 [11][12][13]. Varios interferentes causan problemas para la detección de H 2 O 2 sobre electrodos de carbono debido a que ocurre a altos sobrepotenciales de oxidación, por eso se busca la reacción electrocatalítica sobre electrodos de carbono funcionalizados con otro material, por lo general, nanopartículas metálicas.…”