Monofunctional pyrenes at carbon nanotube electrodes for direct electron transfer H2O2 reduction with HRP and HRP-bacterial nanocellulose

Abstract

The non-covalent modification of carbon nanotube electrodes with pyrene derivatives is a versatile approach to enhance the electrical wiring of enzymes for biosensors and biofuel cells. We report here a comparative study of five pyrene derivatives adsorbed at multi-walled carbon nanotube electrodes to shed light on their ability to promote direct electron transfer with horseradish peroxidase (HRP) for H 2 O 2 reduction. In all cases, pyrene-modified electrodes enhanced catalytic reduction compared to the unmodified electrodes. The pyrene N-hydroxysuccinimide (NHS) ester derivative provided access to the highest catalytic current of 1.4 mA cm -2 at 6 mmol L -1 H 2 O 2 , high onset potential of 0.61 V vs. Ag/AgCl, insensitivity to parasitic H 2 O 2 oxidation, and a large linear dynamic range that benefits from insensitivity to HRP "suicide inactivation" at 4 to 6 mmol L -1 H 2 O 2 . Pyrene-aliphatic carboxylic acid groups offer better sensor sensitivity and higher catalytic currents at ≤ 1 mmol L -1 H 2 O 2 concentrations. The butyric acid and NHS ester derivatives gave high analytical sensitivities of 5.63 A M -1 cm -2 and 2.96 A M -1 cm -2 , respectively, over a wide range (0.25 to 4 mmol -1 ) compared to existing carbon-based HRP biosensor electrodes. A bacterial nanocellulose pyrene-NHS HRP bioelectrode was subsequently elaborated via "one-pot" and "layer-bylayer" strategies. The optimised bioelectrode exhibited slightly weaker voltage output, further enhanced catalytic currents, and a major enhancement in 1-week stability with 67% activity remaining compared to 39% at the equivalent electrode without nanocellulose, thus offering excellent prospects for biosensing and biofuel cell applications.

Horseradish peroxidase-triggered direct in situ fluorescent immunoassay platform for sensing cardiac troponin I and SARS-CoV-2 nucleocapsid protein in serum

“… Akter et al, 2017 , Bhardwaj et al, 2019 , Chen et al, 2012 , Lopa et al, 2019 , Masud et al, 2017 , Ouyang et al, 2021 , Qian et al, 2019 , Sara et al, 2021 , Sun et al, 2018 , Zhang et al, 2019 , Zong et al, 2021 .…”

Utilization of FAD-Glucose Dehydrogenase from T. emersonii for Amperometric Biosensing and Biofuel Cell Devices

“…The strong π–π interactions of DCNQ, TeGDH, and polydopamine with MWCNTs allow improved stability, as shown recently. 44 Moreover, the power output using MET was higher than DET due to a better ET process and lower overpotential. The PDA-based configuration yielded improved currents, thus showing its advantage over DET with the presented methodology.…”

Carbon Nanomaterials (CNMs) and Enzymes: From Nanozymes to CNM-Enzyme Conjugates and Biodegradation

“…Conjugation with CNMs allows for high-performance devices. They have been coupled to enzymes to serve as anodes [ 248 , 251 , 258 , 259 , 269 , 285 ], cathodes [ 253 , 267 , 276 , 277 , 286 ], or both [ 247 , 284 ].…”

“…Wearable CNT-based biofuel cells were developed on a cotton textile that allowed illumination of an LED on the cloth [ 376 ]. Amongst the CNMs that have been used with enzymes in biofuel cells as summarized in Table 1 , CNTs are certainly the mostly studied [ 247 , 248 , 251 , 253 , 258 , 259 , 267 , 269 , 276 , 277 , 284 , 285 , 286 ]. Recently, scientists are recognizing innovation opportunities also in other types of CNMs, such as CNDs [ 229 ], GO [ 242 ] or rGO [ 275 ], although reports in this direction are still very limited.…”