Photoelectrochemical Enzyme Biosensor Based on TiO₂ Nanorod/TiO₂ Quantum Dot/Polydopamine/Glucose Oxidase Composites with Strong Visible-Light Response

Abstract

Although photoelectrochemical (PEC) enzyme biosensors based on visible-light detection would have a high practical value, their development has been limited by the weak visible-light response of available photoactive substrates. Here, to enhance the visible-light response of a photoelectric substrate, a TiO2 nanorods (NRs)/TiO2 quantum dots (QDs)/polydopamine (PDA)/glucose oxidase nanocomposite was prepared via hydrothermal synthesis, followed by photopolymerization. TiO2 QDs with strong light absorption and excellent photocatalytic activity were introduced between the TiO2 NRs and the PDA. An efficient electron transport interface that formed as a result of the combination of the TiO2 NRs, TiO2 QDs, and the PDA could not only transfer electrons quickly and orderly, but also substantially improve the response of the TiO2 NRs under visible light. Through a series glucose detection, a sensor based on the nanocomposite was found to exhibit superior sensing performance under visible light with a sensitivity of 4.63 μA mM–1 cm–2, a linear response over the concentration 0.1–4 mM, and a detection limit of 8.16 μM. This work proposes a biosensor that can detect under visible light, thereby expanding the application range of PEC enzyme biosensors.

High-performance Vo-ZnO/ZnS benefiting nanoarchitectonics from the synergism between defect engineering and surface engineering for photoelectrochemical glucose sensors

“…In this study, the MS test was performed in the dark and fitted to the MS curves using eqn (1). 27 As shown in Fig. 6b, ZnO and Vo-ZnO/ZnS are N-type semiconductors.…”

CdSe/TiO2NTs Heterojunction-Based Nonenzymatic Photoelectrochemical Sensor for Glucose Detection

“…Photoluminescence (PL) was used to study the migration, trapping, and transfer efficiency of photogenerated carriers in the samples Figure c exhibits the PL plots of TiO 2 NTs and CdSe/TiO 2 NTs 1:20.…”

Engineering exposed vertical nano-TiO2 (001) facets/BiOI nanosheet heterojunction film for constructing a satisfactory PEC glucose oxidase biosensor

“…4A shows that, aer BiOI NSs were modied on TiO 2 NSs, the absorption peaks of the samples shied signicantly to the visible region, and the absorption edge increased from 391 nm to 544 nm because BiOI is a narrow band gap semiconductor and could be excited by longer wavelength light, which is benecial to keeping the bioactivity of the enzyme immobilized on the TiO 2 NS/BiOI NS electrode 11 and reducing the occurrence of side reactions in the detection system. 20 The band gap values could be calculated with the following formula: 21 (ahn…”