Carbon dots-decorated multiwalled carbon nanotubes nanocomposites as a high-performance electrochemical sensor for detection of H2O2 in living cells

Abstract

A novel enzyme-free hydrogen peroxide sensor composed of carbon dots (CDs) and multi-walled carbon nanotubes (MWCNTs) was prepared. It was found that the carbon dots-decorated multi-walled carbon nanotubes nanocomposites (CDs/MWCNTs) modified glassy carbon (GC) electrode (CDs/MWCNTs/GCE) exhibited a significant synergistic electrocatalytic activity towards hydrogen peroxide reduction as compared to carbon dots or multi-walled carbon nanotubes alone, and the CDs/MWCNTs/GCE has shown a low detection limit as well as excellent stability, selectivity, and reproducibility. These remarkable analytical advantages enable the practical application of CDs/MWCNTs/GCE for the real-time tracking of hydrogen peroxide (H2O2) released from human cervical cancer cells with satisfactory results. The enhanced electrochemical activity can be assigned to the edge plane-like defective sites and lattice oxygen in the CDs/MWCNTs nanocomposites due to the small amount of decoration of carbon dots on the multi-walled carbon nanotubes. Based on a facile preparation method and with good electrochemical properties, the CDs/MWCNTs nanocomposites represent a new class of carbon electrode for electrochemical sensor applications. Graphical Abstract CDs/MWCNTs exhibited good electrocatalytic activity and stability to H2O2 reduction and can be used for real-time detection of H2O2 released from living cells.

Detection of pH and Enzyme-Free H2O2 Sensing Mechanism by Using GdO x Membrane in Electrolyte-Insulator-Semiconductor Structure

“…A moderate sensitivity of 0.13 mV/μM is obtained from a linear range of 1 to 200 μM whereas it is 82 mV/μM from a linear range of 0.5 to 1 μM. Our detection limit of 1 μM is inferior than the published results [ 9 – 12 , 15 , 16 , 41 – 43 ], comparable with the published results [ 44 – 47 ], and superior than the published results [ 13 , 17 , 18 , 20 , 48 – 52 ] in literature by using different sensing methods, as shown in Table 1 . Further study is needed to improve the detection limit in the future.…”

“…Hao et al [ 19 ] have developed an amperometric H 2 O 2 sensor based on Fe 2 O 3 nanoparticles. Bai et al [ 20 ] have reported a sensor based on carbon dot-decorated multi-walled carbon nano-composites. Silver (Ag) nanowire [ 21 ] and nanoparticle-decorated graphene [ 22 ] have been also reported for H 2 O 2 sensing.…”

Carbon Nanodots in Electrochemical Sensors and Biosensors: A Review

“…It was revealed that the proposed electrode shows high electrocatalytic activity toward H 2 O 2 released from prostate cancer cell (PC‐3) versus non‐cancerous cell (BPH‐1) therefore facilitating the detectability of peroxide [48] . Furthermore, CDs/MWCNTs/GCE displayed a novel electrocatalytic activity towards H 2 O 2 reduction [49] …”

Nanomaterial-Based Electrochemical Hydrogen Peroxide Biosensor

“…9 Horseradish peroxidase (HRP) and catalase (CAT) are the two kinds of enzymes that are commonly used for H 2 O 2 detection. However, the immobilization and stabilization protocol of the enzyme are complicated, and it is difficult to achieve the direct electron transfer on bare electrode.…”