Catalase biosensor based on the PAni/cMWCNT support for peroxide sensing

Abstract

Polymeric-based composites can contribute to enhancing the detection, stability, and performance of enzymatic biosensors, due to their high structural stability, conductivity, and biocompatibility. This work presents the fabrication of a nanocomposite of polyaniline (PAni)/gold nanoparticles (AuNP)/carboxylated multiwalled carbon nanotubes (cMWCNT) as functional support for covalently linked catalase (CAT) enzyme. PAni was electropolymerized on a screen-printed carbon electrode (SPCE) and decorated with AuNP to improve charge transfer properties. CAT was bonded through amide formation using the carboxylic groups of cMWCNT, resulting in PAni/AuNP/cMWCNT/CAT biosensor. The structural and electroactive characteristics of the nanocomposite were studied by SEM, FT-IR, and cyclic voltammetry. The optimal performance was achieved after CAT immobilization over PAni/AuNP/cMWCNT/nanocomposite, showing improved analytical features such as a fast amperometric response of 1.28 s, a wide detection range from 0.01 to 6.8 mM, a correlation coefficient (R 2) of 0.9921, a low detection limit of 2.34 µM, and an average recovery rate of 99.6% when evaluated in milk samples. Additionally, the bioelectrode showed excellent selectivity and retained bioactivity after 30 days of storage. Such remarkable performance proved the synergistic effects of both the high surface area of the cMWCNT and AuNP and the inherent PAni electroactivity, yielding direct electron transfer from CAT.

Cerium oxide nanoparticles in wound care: a review of mechanisms and therapeutic applications

“…The Ce 3+ ions on the surface are the site of catalytic reactions, while the generated oxygen vacancies contribute to the conversion and migration of active substances in the system. All these factors will be favorable for biosensors (Soni et al, 2018;Domínguez-Aragón et al, 2021). The redox activity of cerium oxide can be used as a sensing platform to generate color in the presence of oxidative enzymes acting on the corresponding substrates to produce H 2 O 2 .…”

Electrochemical Immunosensor for the Determination of Nuclear Matrix Protein 22 in Urine Using Carboxylated MWCNTs and Zeolitic Imidazolate Framework Modified with AgNPs

“…For the fabrication of electrochemical immunosensors, working electrodes frequently need to be adjusted to ameliorate their electrochemical properties and reinforce their conductivity. The majority of the materials utilized to affect the electrodes’ properties are nanomaterials, with carbon nanomaterials being the most popular. − Carboxylated multiwalled carbon nanotubes (CMWCNTs) can effectively promote charge transfer and are often used as matrix materials to enhance the conductivity of sensors. , Nanotubes have a large specific surface area and are prone to form a dense film on the electrode, which facilitates the subsequent adsorption of other substances . For example, Assari et al used CMWCNTs as a base material in combination with polyaniline and gold nanoparticles for the detection of prostate-specific antigens, where CMWCNTs significantly enhanced the current signal of this sensor .…”

“…12−14 Carboxylated multiwalled carbon nanotubes (CMWCNTs) can effectively promote charge transfer and are often used as matrix materials to enhance the conductivity of sensors. 15,16 Nanotubes have a large specific surface area and are prone to form a dense film on the electrode, which facilitates the subsequent adsorption of other substances. 17 For example, Assari et al used CMWCNTs as a base material in combination with polyaniline and gold nanoparticles for the detection of prostate-specific antigens, where CMWCNTs significantly enhanced the current signal of this sensor.…”

Modification of screen-printed carbon electrode for detection of pesticides

“…In the past few decades, metal nanoparticles have been the subject of a large number of publications in almost every scientific field including electrochemistry owing to their unique electronic, optical, magnetic and catalytic properties [22]. Basically, gold nanoparticles (AuNPs), which are widely available in more homogeneous nanomaterials with high surface-to-volume ratio, have been extensively employed as electrode modifiers for the fabrication of electrochemical sensors as they can increase the electrode surface area, enhance the electron transfer rate, and subsequently amplify the sensor signal [23]. Literally, it has been previously reported that AuNPs and PANI hybrid could offer remarkable and synergistic combination, leading to the excellent catalytic performance of the sensor [24].…”