Pt Nanoparticle‐modified Carbon Fiber Microelectrode for Selective Electrochemical Sensing of Hydrogen Peroxide

Abstract

We report a simple approach to the production of carbon fiber‐based amperometric microbiosensors for selective detection of hydrogen peroxide (H2O2), which was achieved by electrometallization of carbon fiber microelectrodes (CFMs) by electrodeposition of Pt nanoparticles. The Pt‐carbon hybrid sensing interface provided a sensitivity of 7711±587 μA ⋅ mM−1 ⋅ cm−2, a detection limit of 0.53±0.16 μM (S/N=3), a linear range of 0.8 μM–8.6 mM, and a response time of <2 sec. The morphologies of the Pt nanoparticle‐modified CFMs were characterized by scanning electron microscopy. To achieve selectivity, permseletive layers, polyphenylenediamine (PPD) and Nafion, were deposited resulting in exclusion of the anionic and cationic interferents, ascorbic acid and dopamine, respectively, at their physiologically relevant concentrations. The resultant sensors displayed a sensitivity to hydrogen peroxide of 1381±72 μA ⋅ mM−1 ⋅ cm−2, and a detection limit of 0.86±0.19 μM (S/N=3). This simple and rapid metallization method converts carbon fiber microelectrodes, which are readily accessible, to microscale Pt electrodes in 2 min, providing a platform for oxidase‐based amperometric biosensors with improved spatial resolution over more commonly used platinum electrode array microprobes.

A Mediator‐Free Electroenzymatic Sensing Methodology to Mitigate Ionic and Electroactive Interferents' Effects for Reliable Wearable Metabolite and Nutrient Monitoring

“…To fabricate PtNP‐based sensors, PtNP were electrochemically deposited onto the Au electrode by chronoamperometry at −0.1 V (vs Ag/AgCl) for 10 min in a fresh Pt solution (containing 2.5 × 10 −3 m H 2 PtCl 6 and 1.5 × 10 −3 m formic acid) . A PPD layer was subsequently electrochemically deposited onto the Au/PtNP electrode by applying 0.85 V (vs Ag/AgCl) for 120 s in a fresh PBS solution (1×) containing 5 × 10 −3 m m ‐phenylenediamine.…”

Micro- and nano-devices for electrochemical sensing

“…Hydrogen peroxide is an important biomarker of oxidative stress, and its detection is essential for the majority of oxidase-based biosensors. Examples of amperometric H 2 O 2 sensors were reported using nano-sized Ag particles [ 63 ] and Pt NP [ 64 ]–modified CF microelectrodes, both of them employing Nafion and/or PPD membranes to achieve the desired selectivity. In the first case, H 2 O 2 decomposition over MnO 2 catalyst was monitored in real time exploiting its reduction at 0 mV vs Ag/AgCl, including high decomposition rates conditions that are typically inaccessible for titrimetric, chromatographic, or spectroscopic methods [ 63 ].…”

Recent Progress of the Practical Applications of the Platinum Nanoparticle-Based Electrochemistry Biosensors

“…Its detection range was between 0.1–2 mM whereas the sensitivity was 33.66 μA/mM cm −2 ; however, the sensitivity of the composite for hydrogen peroxide needs further improvement. Wang et al ( 2019 ) prepared an oxidase-based hydrogen peroxide biosensor through electrodeposition of Pt nanoparticles on carbon fiber microelectrodes. The Pt–carbon hybrid sensor had a sensitivity of 7,711 ± 587 uA·mM −1 cm −2 , a detection limit of 0.53 ± 0.16 μM, and a linear range of 0.8 μM−8.6 mM.…”

“…Based on the rGO–Pt nanocomposites, Zhao et al ( 2017 ) fabricated an amperometric H 2 O 2 biosensor using iron oxide-reduced graphene oxide (Fe 3 O 4 /rGO) nanocomposite (Hummers and Offeman, 1958 ; Wu et al, 2012 ; Sanzo et al, 2017 ; Zhao et al, 2017 ; Wang et al, 2019 ). They electrodeposited the Pt with a GCE.…”