Bioinspired Surface Modification of Graphene-Based Hybrids as Nanozyme Sensors for Simultaneous Detection of Dopamine and Uric Acid

Abstract

Development of hybrid nanozymes with high catalytic efficiency is of critical importance for enzyme mimics in biological catalytic fields. Herein, we reported a polydopamine (PDA) surface modification-assisted pyrolysis strategy for preparing CoO nanoparticles/N-doped carbon sheets/reduced graphene oxide composites (CoO/N-CS-rGO). In this strategy, PDA with abundant amines and imines could serve as an eco-friendly N-contained precursor and a connecting agent between GO matrix and CoO. Due to the superior conductivity of N-CS-rGO, synergistic catalysis between CoO nanoparticles (NPs) and N-CS-rGO, and intrinsic oxidase-like characteristic, the CoO/N-CS-rGO was used as an ultrasensitive signal amplification platform for simultaneously analyzing dopamine (DA) and uric acid (UA) in a neutral solution. Significantly, the fabricated electrochemical sensor showed ultrahigh sensitivities of 1378 μA mM–1 for DA and 1393 μA mM–1 for UA. The linear range of 0.5–110 μM for DA and 1–125 μM for UA could be obtained by this sensor. Furthermore, the stability and selectivity of the CoO/N-CS-rGO-based hybrid biosensor were evaluated. The results showed that the biosensor performed good stability and brilliant selectivity against interfering analytes. Also, the CoO/N-CS-rGO/GCE was adopted to monitor two analytes in human serum samples with high accuracy. This work provides an efficient PDA-assisted synthetic strategy to prepare hybrid nanomaterials and shows broad prospects for biosensing, biotechnology, and clinical diagnosis.

Nanozyme Sensor Based on Au Nanoparticles/N-Doped Porous Carbon Composites for Biosensing

“…The Nyquist plots could be divided into two regions, in which the straight portion is associated with the diffusion-limited procedure and the semicircle part corresponds to the electron-transfer-limited process. The semicircle region in the Nyquist plot is equivalent to the charge-transfer resistance ( R ct ) value of the electrodes . For the bare GCE, the R ct value is 270.5 Ω. Interestingly, the semicircle regions disappear after modification of the NPC and AuNPs/NPC, indicating the excellent conductivity of the prepared electrodes.…”

“…The semicircle region in the Nyquist plot is equivalent to the charge-transfer resistance (R ct ) value of the electrodes. 51 For the bare GCE, the R ct value is 270.5 Ω. Interestingly, the semicircle regions disappear after modification of the NPC and AuNPs/NPC, indicating the excellent conductivity of the prepared electrodes. The R ct values of NPC/GCE and AuNPs/ NPC/GCE are 19.1 and 14.6 Ω, respectively.…”

Nanoengineered parallelogram-NiFe2O4/rGO nanocomposite-based biosensing interface for highly efficient electrochemical detection of neurodegenerative disorders via dopamine monitoring

“…Ali et al 58 developed barium titanate "nanocubes" as dual electrochemical sensors for DA monitoring on a glassy carbon electrode (GCE) in a linear range of 10 to 100 μM: the LOD was 0.35 μM. Lu et al 59 utilized a CoO nanoparticles/N-doped carbon sheets/ reduced graphene oxide composites (CoO/N-CS-rGO) fabricated electrode on GCE to develop a hybrid nanozyme sensor for DA detection in human serum samples in the range 0.5 to 110 μM: the LOD was 0.15 μM. Liu et al 60 developed an electrochemical sensor based on the Fe 2 O 3 -NG/ GCE electrode to optimize the DA concentration in the range 0.5 to 10 μM: the LOD was 0.080 μM in the standard sample and sample of human serum.…”

Review—Catalytic Electrochemical Biosensors for Dopamine: Design, Performance, and Healthcare Applications

“…147 Lu et al used reduced graphene oxide composites of CoO NPs and Ndoped carbon sheets on a GCE, providing an LOD of 150 nM and a linear range of 0.5-110 μM. 159 Another cobalt-based nanozyme with a bamboo-like nitrogen-doped carbon nanotube structure demonstrated an LOD of 34.2 nM and linear range of 0.5-150 μM DA, and was successfully applied for detection of dopamine in human serum. 156 Ma et al was able to further increase their sensors detection capabilities by using bifunctional nanozymatic hollow core-shell CuS@CuSe heteromicrocubes leading to an LOD of 0.38 nM and linear ranges of 0.002-0.44 and 0.52-1.66 μM DA.…”