A Core–Shell Au@TiO2 and Multi-Walled Carbon Nanotube-Based Sensor for the Electroanalytical Determination of H2O2 in Human Blood Serum and Saliva

Abstract

A hydrogen peroxide (H2O2) sensor was developed based on core–shell gold@titanium dioxide nanoparticles and multi-walled carbon nanotubes modified by a glassy carbon electrode (Au@TiO2/MWCNTs/GCE). Core–shell Au@TiO2 material was prepared and characterized using a scanning electron microscope and energy dispersive X-ray analysis (SEM/EDX), transmission electron microscopy (TEM), atomic force microscope (AFM), Raman spectroscopy, X-ray diffraction (XRD) and Zeta-potential. The proposed sensor (Au@TiO2/MWCNTs/GCE) was investigated electrochemically using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The analytical performance of the sensor was evaluated towards H2O2 using differential pulse voltammetry (DPV). The proposed sensor exhibited excellent stability and sensitivity with a linear concentration range from 5 to 200 µM (R2 = 0.9973) and 200 to 6000 µM (R2 = 0.9994), and a limit of detection (LOD) of 1.4 µM achieved under physiological pH conditions. The practicality of the proposed sensor was further tested by measuring H2O2 in human serum and saliva samples. The observed response and recovery results demonstrate its potential for real-world H2O2 monitoring. Additionally, the proposed sensor and detection strategy can offer potential prospects in electrochemical sensors development, indicative oxidative stress monitoring, clinical diagnostics, general cancer biomarker measurements, paper bleaching, etc.

Electrochemical sensors for analyte in saliva: recent update

“…Its high electrochemical performance is attributed to the multifunctional combination of layers, benefiting from N-doped carbon’s conductivity and electron transfer abilities, as well as TiO 2 ’s electrocatalytic activity. Similarly, a H 2 O 2 sensor was developed using core-shell Au@TiO 2 and MWCNT (Au@TiO 2 /MWCNTs) [Figure 9(d)] (Saeed et al , 2022). The sensor exhibited excellent stability and sensitivity, with a linear concentration range from 5 to 200 µM and 200 to 6,000 µM, and a detection limit of 1.4 µM under physiological pH conditions.…”

Enzymatic Electrochemical Biosensors for Neurotransmitters Detection: Recent Achievements and Trends

“…Electrochemical transducers are the most commonly used transducers in the construction of innovative biosensing applications. Electrochemical analysis has advantages over other measurement systems in terms of being rapid, simple, portable, and able to be easily miniaturized [36,37].…”

Advanced Nanostructured Coatings Based on Doped TiO2 for Various Applications

“…The biosensors can detect the following: cancer [139,[182][183][184]; cholesterol [185]; COVID-19 [186,187], DNA [177,[188][189][190]; dopamine [191]; and glucose with PEC [175,176,192,193], amperometry [194], mpedimetry [195,196], electrochemical [197], glucose oxidase film [198][199][200]; hydrogen peroxide (H 2 O 2 ) [201,202]; lactose [203,204]; myoglobin [205]; serine [206]; urea [207,208]; viral diagnostics [209]; and other methods [190,193,210]. PEC biosensors were obtained using a nanosheet composite based on TiO 2 and g-C 3 N 4 , which were able to detect glucose even at concentrations as low as 0.01 mM [211].…”