A Highly Sensitive Hydrogen Peroxide Biosensor Based on Hemoglobin Immobilized on Cadmium Sulfide Quantum Dots/Chitosan Composite Modified Glassy Carbon Electrode

Abstract

An L‐cysteine capped cadmium sulfide‐chitosan nanocomposite has been synthesized, characterized and used for surface modification of a glassy carbon electrode. With direct electron transfer, hemoglobin (Hb) adsorbed strongly on the nanocomposite and displayed excellent bioelectrocatalysis for H2O2. The biosensor was capable of reducing H2O2 at −0.35 V, with a detection limit of 3.13 nM, linearity in the range of 15 nM to 10 µM and a response time of less than 2 s. The MichaelisMenten constant (KM) was 0.57 nM, attesting high bioelectrocatalysis of immobilized Hb for H2O2. Reproducibility of the fabrication method was very satisfactory with a relative standard deviation of 5.3 %. The biosensor lost only 6.5 % of its original response after 7 days when stored in a pH 7.4 PBS at 4 °C.

An Electrochemical Cholesterol Biosensor Based on A CdTe/CdSe/ZnSe Quantum Dots—Poly (Propylene Imine) Dendrimer Nanocomposite Immobilisation Layer

“…Another group of nanomaterials of interest in biosensor design are quantum dots (QDs) [ 18 , 38 , 39 ]. Owing to their nanoscopic size similar to proteins, they can be used to improve the surface area of the electrode leading to increase in electrochemical response and bio-receptor loading [ 38 , 40 , 41 , 42 , 43 ].…”

Synthesis of copper sulfide nanorods as peroxidase mimics for the colorimetric detection of hydrogen peroxide

“…29 In fact, the determination of trace H 2 O 2 itself is also very important and necessary in environmental and clinical analysis. Many methods such as spectrouorometry, 30,31 electroanalysis, [32][33][34][35] and chemiluminescence 36 have been developed for the detection of H 2 O 2 ; however, these methods have disadvantages such as requiring expensive or sophisticated instruments and as they cannot be applied to real-time or eld analysis. Nanoparticles used in enzyme mimics-based colorimetric biosensors have emerged as an important tool for the real-time and on-site detection of H 2 O 2 .…”

Oxygen Reduction Reaction of Hemoglobin on Indium-Tin-Oxide Electrodes and Its Application to Biofuel Cell Cathode

“…Each globin has one iron-bearing heme group hence four redox active centers are located near the surface of the protein shell (2,17,18). Great efforts have been mainly conducted by a mediated electron transfer including modified or immobilized electrodes in the Hb electrochemistry (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). On the other hand, we have successfully observed direct electron transfer characteristics and the electrocatalysis for H 2 O 2 of Hb and O 2 reduction by red blood cells (RBCs) on bare indium-tin oxide (ITO) electrodes (16,(31)(32)(33)(34).…”