Preparation of a Magnetically Switchable Bio‐electrocatalytic System Employing Cross‐linked Enzyme Aggregates in Magnetic Mesocellular Carbon Foam

Abstract

Nanostructured magnetic materials (NMMs) [1] have attracted much attention recently because of their broad biotechnological applications including support matrices for enzyme immobilization, [2] immunoassays, [3] drug delivery, [4] and biosensors.[5]

Fabrication of Nanoporous Nanocomposites Entrapping Fe3O4 Magnetic Nanoparticles and Oxidases for Colorimetric Biosensing

“…The oxidative enzyme is then immobilized on the MMS using the glutaraldehyde crosslinking method which prevents enzymes leaching from the pores. [30][31][32][33] This leads to over 20 wt% loading of the enzyme. We envisioned that the nanostructure obtained by entrapping the enzyme into MMS would serve as an efficient biosensor capable of being used for colorimetric detection of biologically important target molecules.…”

A simple method to ordered mesoporous carbons containing nickel nanoparticles

“…Incorporation of magnetic metal or metal oxide nanoparticles into OMCs without the blockage of mesoporosity is of great interest since it enables an alternative and simple separation of OMCs by means of an external magnetic field. Therefore, such composite materials are potentially useful as magnetically separable catalysts (Lee et al 2005b), catalyst supports (Lu et al 2004;Tian et al 2007), and adsorbents (Cao et al 2007b).…”

“…For example, Lu et al fabricated magnetic CMK-3 by depositing Co nanoparticles on the outer surface of a carbon/SBA-15 composite with coating of a thin carbon layer on Co nanoparticles to anchor them on the surface of CMK-3 and to prevent dissolution by HF. This method could be simplified by impregnation of a solution of iron salt or nickel salt into the pores of C/silica composites or OMCs, followed by the reduction of iron or nickel salt into magnetic Fe 3 O 4 (Lee et al 2005b;Tian et al 2007) or Ni nanoparticles (Cao et al 2007b), respectively. In the second method, ordered mesoporous silicas were pre-loaded with magnetic nanoparticles before filling the carbon precursor (Holmes et al 2005), or were impregnated with both the carbon precursor and metal salts.…”

“…The first method is to deposit or load magnetic nanoparticles on the presynthesized OMCs, which are prepared using ordered mesoporous silicas as the hard templates (Cao et al 2007b;Lee et al 2005b;Lu et al 2004;Tian et al 2007). For example, Lu et al fabricated magnetic CMK-3 by depositing Co nanoparticles on the outer surface of a carbon/SBA-15 composite with coating of a thin carbon layer on Co nanoparticles to anchor them on the surface of CMK-3 and to prevent dissolution by HF.…”

Electrode Interfaces Switchable by Physical and Chemical Signals Operating as a Platform for Information Processing

“…Various physical and/or chemical signals as well as their combinations were used to switch electrochemical properties of the modified interfaces between active and inactive states for specific electrochemical, electrocatalytic, and bioelectrocatalytic reactions. Light signals (irradiation of electrodes with visible or ultraviolet light) [24-31], magnetic field applied at electrode surfaces loaded with magnetic particles or magnetic nanowires [32][33][34][35][36][37][38][39][40][41][42][43], and electrical potentials producing chemical changes at the electrode surfaces [44][45][46][47][48] were used to reversibly alternate electrochemical properties of the modified electrodes. Chemical [29,[49][50][51] or biochemical [52] signals resulting in reversible changes of the interfacial properties were also used to switch the electrode activity ON/OFF for specific electrochemical transformations.…”