การพัฒนานาโนเทคโนโลยีสำหรับประยุกต์ใช้เป็นเซนเซอร์ด้านการแพทย์

Abstract

A novel composite material of copper (I) oxide at manganese (IV) oxide (Cu2O@MnO2), was synthesized and applied for modification on the glassy carbon electrode (GCE) surface (Cu2O@MnO2/GCE) as a hydrogen peroxide (H2O2) sensor. The composite material was characterized regarding its structural and morphological properties using field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The Cu2O@MnO2/GCE showed an excellent electrocatalytic response to the oxidation of H2O2 which provided a 0.56 s-1 charge transfer rate constant, 1.65 x 10-5 cm2 s-1 diffusion coefficient value, 0.12 mm2 electroactive surface area and 1.04 x 10-8 mol cm-2 surface concentration. At the optimal condition, the constructed sensor exhibited a wide linear range from 0.5 µM to 20 mM with a low limit of detection of 63 nM. (S/N = 3) and a good sensitivity of 256.33 µA mM-1 cm-2. It also presented high stability (± 15.00%, n=100), repeatability (1.25% RSD, n=10) and reproducibility (3.55% RSD, n=10). The results indicated that the synthesized Cu2O@MnO2 was successfully used as a new platform for H2O2 sensing. A novel metal composite material based on zirconium dioxide coated gold nanoparticles (ZrO2@AuNPs), copper (I) oxide at manganese (IV) oxide (Cu2O@MnO2) and immobilized choline oxidase (Cox) onto a glassy carbon electrode (GCE) (Cox/Cu2O@MnO2/ZrO2@AuNPs/GCE) has been developed for enhancing the electrocatalytic property, sensitivity and stability of the amperometric choline biosensor. The Cox/Cu2O@MnO2/ZrO2@AuNPs/GCE displayed an excellent electrocatalytic response to the oxidation of the byproduct H2O2 from the choline catalyzed reaction, which exhibited charge transfer rate constant of 0.97 s-1, diffusion coefficient value 4.50×10-6 cm2 s-1, electroactive surface area 0.24 mm2 and surface concentration 0.54×10-8 mol cm-2. The modified electrode also provided a wide linear range of choline concentration from 0.5 to 1,000.0 μM with good sensitivity (97.4 μA cm-2 mM-1) and low detection limit (0.3 μM). This choline biosensor presented high repeatability (%RSD = 2.90, n = 5), excellent reproducibility (%RSD = 2.90, n = 5), long time usage (n = 28 with %I > 50.0%) and good selectivity without interfering effects from possible electroactive species such as ascorbic acid, aspirin, amoxicillin, caffeine, dopamine glucose, sucrose and uric acid. This optimal method was successfully applied for choline measurement in human blood samples which demonstrated highly accurate and excellent reliability in the recovery range from 97.10 to 103.90%.