Comparison between electrochemical and photoelectrochemical detection of dopamine based on titania-ceria-graphene quantum dots nanocomposite

Ahmadi, N ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1016/j.bios.2019.111977
  3. Publisher: Elsevier Ltd , 2020
  4. Abstract:
  5. In this study, titania-ceria-graphene quantum dot (TC-GQD) nanocomposite was synthesized by hydrothermal method for the first time. The prepared nanomaterials were characterized by XRD, FTIR dynamic light scattering (DLS), FESEM, HRTEM, and EDX spectroscopy along with elemental mapping. The synergistic effect of the nanocomposite components was studied by diffuse reflectance spectroscopy (DRS) and electrical conductivity meter. The results showed that band gap of TC-GQD nanocomposite was shifted to visible lights relative to its components (1.3 eV), and electrical conductivity of the sample was significant increased to 89.5 μS cm−1. After chemical and physical characterization, prepared new nanocomposites were used to design a new electrochemical (EC) and photoelectrochemical (PEC) dopamine (DA) sensors. In both EC and PEC methods effecting experimental parameters were optimized. Due to the synergic effect of the nanocomposite components, an outstanding photocurrent response was observed for DA based on PEC sensor. A linear calibration curve with a lower detection limit of 22 nM DA, and sensitivity of 13.8 mA/mM(DA), in a wider range of 0.3–750 μM DA, was obtained for TC-GQD/GCE electrode in PEC. While, the TC-GQD/GCE electrode detected DA in the range of 1–500 μM DA, with two linear calibration curve, detection limit of 0.22 μM DA, and sensitivity of 4.9 mA/mM(DA), in the EC. Observed results from EC and PEC sensors are presented and compared. © 2019 Elsevier B.V
  6. Keywords:
  7. Graphene quantum dot ; Photoelectrochemical sensor ; Synergistic effect ; Amines ; Calibration ; Cerium oxide ; Chemical detection ; Dynamic light scattering ; Electric conductivity of solids ; Electrodes ; Energy gap ; Fourier transform infrared spectroscopy ; Graphene ; Nanocrystals ; Neurophysiology ; Semiconductor quantum dots ; Diffuse reflectance spectroscopy ; Electrical conductivity ; Experimental parameters ; Linear calibration curve ; Photoelectrochemical sensors ; Physical characterization ; Photoelectrochemical cells ; Titania ceria graphene quantum dot ; Unclassified drug ; Ceric oxide ; Dopamine ; Graphite ; Metal nanoparticle ; Quantum dot ; Titanium dioxide ; Controlled study ; Electrochemical analysis ; Electrochemical detection ; Energy dispersive X ray spectroscopy ; Field emission scanning electron microscopy ; High resolution transmission electron microscopy ; Limit of detection ; Photoelectrochemical detection ; Photon correlation spectroscopy ; Process optimization ; Sensitivity analysis ; Synthesis ; X ray diffraction ; Chemistry ; Genetic procedures ; Human ; Isolation and purification ; Biosensing Techniques ; Cerium ; Electrochemical Techniques ; Metal Nanoparticles ; Nanocomposites ; Quantum Dots ; Titanium
  8. Source: Biosensors and Bioelectronics ; Volume 151 , 2020
  9. URL: https://www.sciencedirect.com/science/article/abs/pii/S0956566319310541