Photoinducedly electrochemical preparation of Prussian blue film and electrochemical modification of the film with cetyltrimethylammonium cation

Expanded detection range of lateral flow immunoassay endowed with a third-stage amplifier indirect probe

Here, a third-stage amplifier indirect probe (TsAIP) based lateral flow immunoassay (LFIA) was proposed to detect furazolidone (FZD) with Prussian blue nanoparticles (PBNPs) as carrier to label the goat anti-mouse antibody-horseradish peroxidase conjugation [GAMA(HRP)]. In this strategy, owing to the fact that one monoclonal antibody (mAb) can combine several GAMA molecules simultaneously, the indirect probe can generate primary signal amplification, then realize second-stage amplification attributing to PBNPs, and finally achieve third-stage amplification because of the conjugated HRP. The TsAIP-based LFIA shows improved performance for FZD metabolite derivative with a detection limit of 1 ng mL^-1. The detection range is expanded about 2-fold compared with the original outcome. Besides, the proposed sensor could be successfully applied in food samples. This method provides a platform for broadening the detection range and application of PBNPs based LFIAs.

Prussian blue-embedded carboxymethyl cellulose nanofibril membranes for removing radioactive cesium from aqueous solution

In this study, we synthesized a Prussian blue (PB)-embedded macroporous carboxymethyl cellulose nanofibril (CMCNF) membrane for facile cesium (Cs) removal. The PB was formed in situ at Fe³⁺ sites on a CMCNF framework cross-linked using FeCl₃ as a cross-linking agent. Cubic PB particles of size 5-20 nm were observed on the macroporous CMCNF membrane surface. The PB-CMCNF membrane showed 2.5-fold greater Cs adsorption capacity (130 mg/g_PB-CMCNF) than commercial PB nanoparticles, even though the PB loading of the PB-CMCNF membrane was less than 100 mg/g_PB-CMCNF. The macroporous structure of the CMCNF membrane led to improved diffusion in the solution, thereby increasing the Cs adsorption capacity. The Cs adsorption behavior was systematically investigated in different solution chemistry. Finally, ¹³⁷Cs removal using a semicontinuous adsorption module was demonstrated in real seawater. The results showed that the PB-CMCNF membrane is a highly effective, practical material for the removal of ¹³⁷Cs from aqueous environments.

Cellulose nanofiber backboned Prussian blue nanoparticles as powerful adsorbents for the selective elimination of radioactive cesium

On 11 March 2011, the day of the unforgettable disaster of the 9 magnitude Tohoku earthquake and quickly followed by the devastating Tsunami, a damageable amount of radionuclides had dispersed from the Fukushima Daiichi's damaged nuclear reactors. Decontamination of the dispersed radionuclides from seawater and soil, due to the huge amounts of coexisting ions with competitive functionalities, has been the topmost difficulty. Ferric hexacyanoferrate, also known as Prussian blue (PB), has been the most powerful material for selectively trapping the radioactive cesium ions; its high tendency to form stable colloids in water, however, has made PB to be impossible for the open-field radioactive cesium decontamination applications. A nano/nano combinatorial approach, as is described in this study, has provided an ultimate solution to this intrinsic colloid formation difficulty of PB. Cellulose nanofibers (CNF) were used to immobilize PB via the creation of CNF-backboned PB. The CNF-backboned PB (CNF/PB) was found to be highly tolerant to water and moreover, it gave a 139 mg/g capability and a million (10⁶) order of magnitude distribution coefficient (K_d) for absorbing of the radioactive cesium ion. Field studies on soil and seawater decontaminations in Fukushima gave satisfactory results, demonstrating high capabilities of CNF/PB for practical applications.

New faces of porous Prussian blue: interfacial assembly of integrated hetero-structures for sensing applications

Prussian blue (PB), the oldest synthetic coordination compound, is a classic and fascinating transition metal coordination material. Prussian blue is based on a three-dimensional (3-D) cubic polymeric porous network consisting of alternating ferric and ferrous ions, which provides facile assembly as well as precise interaction with active sites at functional interfaces. A fundamental understanding of the assembly mechanism of PB hetero-interfaces is essential to enable the full potential applications of PB crystals, including chemical sensing, catalysis, gas storage, drug delivery and electronic displays. Developing controlled assembly methods towards functionally integrated hetero-interfaces with adjustable sizes and morphology of PB crystals is necessary. A key point in the functional interface and device integration of PB nanocrystals is the fabrication of hetero-interfaces in a well-defined and oriented fashion on given substrates. This review will bring together these key aspects of the hetero-interfaces of PB nanocrystals, ranging from structure and properties, interfacial assembly strategies, to integrated hetero-structures for diverse sensing.

Application of cetyltrimethylammonium bromide bentonite-titanium dioxide photocatalysis technology for pretreatment of aging leachate

Organobentonite-photocatalysis technology was applied to pretreat aging leachate containing refractory pollutants. The organobentonite was synthesized by organic modifier cetyltrimethylammonium bromide (CTMAB) and natural bentonite. In characterization experiments, we could confirm that organic functional groups of cetyltrimethylammonium (CTMA(+)) cations were successfully loaded on the surface of bentonite. The combination of CTMAB2.5 adsorption and TiO2 photocatalysis was superior to either running separately. Furthermore, removal efficiency of simultaneously utilizing CTMAB2.5 and TiO2 was better than them in succession. The combination technology was feasible and was optimized by response surface methodology (RSM) with COD and NH3-N removal rate as the target responses. The optimal operation conditions calculated from the regression equations were CTMAB2.5 dosage of 7.5 g/L, pH at 3.5, TiO2 dosage of 1.63 g/L, and reaction time for 60.02 min, which maintained the removal of COD and NH3-N at 82% and 37%, respectively.

Prussian blue caged in alginate/calcium beads as adsorbents for removal of cesium ions from contaminated water

Prussian blue encapsulated in alginate beads reinforced with highly dispersed carbon nanotubes were prepared for the safe removal of cesium ions from aqueous solutions. Equilibrium and kinetic studies were conducted using different models and the goodness of mathematical fitting of the experimental data on the adsorption isotherms was in the order Langmuir>Freundlich, and that of the kinetic models were in the order of pseudo second order>pseudo first order. Fixed bed adsorption column analysis indicated that the beads can be used for large scale treatment of cesium contaminated water.

Complete dechlorination of 2,4-dichlorophenol in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel composite electrode

The electrochemically reductive dechlorination of 2,4-dichlorophenol (2,4-DCP) in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel electrode (Pd/PPy-CTAB/foam-Ni electrode) was investigated in this paper. Pd/PPy-CTAB/foam-Ni electrode was prepared and characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) adsorption and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The influences of some experimental factors such as the dechlorination current, dechlorination time and the initial pH on the removal efficiency and the current efficiency of 2,4-DCP dechlorination on Pd/PPy-CTAB/foam-Ni electrode were studied. Complete removal of 2,4-DCP was achieved and the current efficiency of 47.4% could be obtained under the conditions of the initial pH of 2.2, the dechlorination current of 5 mA and the dechlorination time of 50 min when the initial 2,4-DCP concentration was 100 mg L(-1). The analysis of high performance liquid chromatography (HPLC) identified that the intermediate products were 2-chlorophenol (2-CP) and 4-chlorophenol (4-CP). The final products were mainly phenol. Its further reduction product cyclohexanone was also detected. The electrocatalytic dechlorination pathways of 2,4-DCP on Pd/PPy-CTAB/foam-Ni electrode were discussed. The stability of the electrode was favorable that it could keep dechlorination efficiency at 100% after having been reused 10 times. Results revealed that the stable prepared Pd/PPy-CTAB/foam-Ni electrode presented a good application prospect in dechlorination process with high effectiveness and low cost.

Recent advances in electrochemical sensing for hydrogen peroxide: a review

Due to the significance of hydrogen peroxide (H(2)O(2)) in biological systems and its practical applications, the development of efficient electrochemical H(2)O(2) sensors holds a special attraction for researchers. Various materials such as Prussian blue (PB), heme proteins, carbon nanotubes (CNTs) and transition metals have been applied to the construction of H(2)O(2) sensors. In this article, the electrocatalytic H(2)O(2) determinations are mainly focused on because they can provide a superior sensing performance over non-electrocatalytic ones. The synergetic effect between nanotechnology and electrochemical H(2)O(2) determination is also highlighted in various aspects. In addition, some recent progress for in vivo H(2)O(2) measurements is also presented. Finally, the future prospects for more efficient H(2)O(2) sensing are discussed.