Amperometric sensing of hydrogen peroxide on a modified electrode with layered Au/TiO2 nanofilms from self-assembly at air/water interface

Mesoporous TiO2-based architectures as promising sensing materials towards next-generation biosensing applications

In the past two decades, mesoporous TiO2 has emerged as a promising material for biosensing applications. In particular, mesoporous TiO2 materials with uniform, well-organized pores and high surface areas typically exhibit superior biosensing performance, which includes high sensitivity, broad linear response, low detection limit, good reproducibility, and high specificity. Therefore, the development of biosensors based on mesoporous TiO2 has significantly intensified in recent years. In this review, the expansion and advancement of mesoporous TiO2-based biosensors for glucose detection, hydrogen peroxide detection, alpha-fetoprotein detection, immobilization of enzymes, proteins, and bacteria, cholesterol detection, pancreatic cancer detection, detection of DNA damage, kanamycin detection, hypoxanthine detection, and dichlorvos detection are summarized. Finally, the future perspective and research outlook on the utilization of mesoporous TiO2-based biosensors for the practical diagnosis of diseases and detection of hazardous substances are also given.

Core-shell iron oxide-layered double hydroxide: High electrochemical sensing performance of H2O2 biomarker in live cancer cells with plasma therapeutics

In this work, we develop a new type of multifunctional core-shell nanomaterial by controllable integration of CuAl layered double hydroxides (LDHs) over the surface of iron oxides (Fe₃O₄) nanospheres (NSs) to fabricate (Fe₃O₄@CuAl NSs) hybrid material with interior tunability of LDH phase and explore its practical application in ultrasensitive detection of emerging biomarker, i.e., H₂O₂ as cancer diagnostic probe. In addition, atmospheric pressure plasmas (APPs) have also been used as potential therapeutic approach for cancer treatment. Due to the synergistic combination of p-type semiconductive channels of LDHs with multi-functional properties, unique morphology and abundant surface active sites, the Fe₃O₄@CuAl NSs modified electrode exhibited attractive electrocatalytic activity towards H₂O₂ reduction. Under the optimized conditions, the proposed biosensor demonstrated striking electrochemical sensing performances to H₂O₂ including linear range as broad as 8 orders of magnitude, low real detection limit of 1nM (S/N = 3), high sensitivity, good reproducibility and long-term stability. Arising from the superb efficiency, the electrochemical biosensor has been used for in vitro determination of H₂O₂ concentrations in human urine and serum samples prior to and following the intake of coffee, and real-time monitoring of H₂O₂ efflux from different cancer cell lines in normal state and after plasma treatment. We believe that this novel nano-platform of structurally integrated core-shell nanohybrid materials combined with APPs will enhance diagnostic as well as therapeutic window for cancer diseases.

Shape-controlled synthesis of three-dimensional triangular bismuth microstructures and sensing of H2O2

The electrodeposition of triangular microstructures of Bi on indium tin oxide surfaces is carried out by optimizing the potentials, precursor concentrations and deposition times.

Highly branched RuO2 nanoneedles on electrospun TiO2 nanofibers as an efficient electrocatalytic platform

Highly single-crystalline ruthenium dioxide (RuO2) nanoneedles were successfully grown on polycrystalline electrospun titanium dioxide (TiO2) nanofibers for the first time by a combination of thermal annealing and electrospinning from RuO2 and TiO2 precursors. Single-crystalline RuO2 nanoneedles with relatively small dimensions and a high density on electrospun TiO2 nanofibers are the key feature. The general electrochemical activities of RuO2 nanoneedles-TiO2 nanofibers and Ru(OH)3-TiO2 nanofibers toward the reduction of [Fe(CN)6](3-) were carefully examined by cyclic voltammetry carried out at various scan rates; the results indicated favorable charge-transfer kinetics of [Fe(CN)6](3-) reduction via a diffusion-controlled process. Additionally, a test of the analytical performance of the RuO2 nanoneedles-TiO2 nanofibers for the detection of a biologically important molecule, hydrogen peroxide (H2O2), indicated a high sensitivity (390.1 ± 14.9 μA mM(-1) cm(-2) for H2O2 oxidation and 53.8 ± 1.07 μA mM(-1) cm(-2) for the reduction), a low detection limit (1 μM), and a wide linear range (1-1000 μM), indicating H2O2 detection performance better than or comparable to that of other sensing systems.