Flow injection enzymatic biosensor for aldehydes based on a Meldola Blue-Ni complex electrochemical mediator

Highly Stable, Cold-Active Aldehyde Dehydrogenase from the Marine Antarctic Flavobacterium sp. PL002

“…Interestingly, in the case of F-ALDH, the NAD + -dependent oxidation of benzaldehyde was not inhibited by the substrate excess, unlike the NADP + -dependent reaction that was inhibited by concentrations of this substrate above 15 mM. Furthermore, based on the good affinity of this cold-active ALDH for benzaldehyde, an electrochemical assay using the enzyme in solution and a stable biosensor for benzaldehyde using immobilized F-ALDH were developed [79]. The biosensor was suitable for the determination of benzaldehyde impurities in benzyl alcohol, a non-active ingredient in liquid drugs.…”

“…While immobilization could lead to a certain loss in enzymatic activity and to changes in the substrate specificity or substrate inhibition, the advantages of immobilization for bioreactors for many industrial applications or for the development of analytical devices, such as biosensors, are undeniable. For example, immobilization of F-ALDH by cross-linking with glutaraldehyde in a matrix of bovine serum albumin (a largely used method in the biosensing field) led to a change in Km from 145 µmol/L to 386 µmol/L [79]. Nonetheless, the immobilization enabled repeatable measurements in a flow injection system for over three days of extensive use at 60 tests/day [79].…”

“…For example, immobilization of F-ALDH by cross-linking with glutaraldehyde in a matrix of bovine serum albumin (a largely used method in the biosensing field) led to a change in Km from 145 µmol/L to 386 µmol/L [79]. Nonetheless, the immobilization enabled repeatable measurements in a flow injection system for over three days of extensive use at 60 tests/day [79]. Other methods enabling controlled quantitative enzyme immobilization, such as exploiting the nickel-histidine affinity in the case of His-tagged enzymes [84], immobilization on nanomaterials with high loading capacities [85], enzyme nanoflowers [86], CLEAs, or other recent strategies [83] could lead to better performance of immobilized F-ALDH.…”

Advances in the Detection of Dithiocarbamate Fungicides: Opportunities for Biosensors

“…Moreover, the homologous recombinant enzyme from the same family originating from the Antarctic Flavobacterium PL002 strain was recently used in an electrochemical test and in a biosensor for the detection of benzaldehyde [ 89 , 103 ]. The enzyme has wide substrate specificity and was shown to be inhibited by thiram [ 104 ], thus it appears to be a good candidate as a biorecognition element in a biosensor for DTFs.…”

Electrochemical operational principles and analytical performance of Pd-based amperometric nanobiosensors

“…Prussian Blue and Meldola Blue) can be employed to facilitate electron-transfer between the bioreceptor and transducer, and to decompose the formed hydrogen peroxide via electrocatalytic redoxreaction. [1][2][3][4] However, some redox mediators (electrocatalysts) used in amperometric glucose or alcohol sensitive biosensors are prone to mechanical instability that leads to their leakage from the electrode surface and degradation of the signal, insufficient sensor sensitivity and selectivity, and low repeatability and accuracy. 5 As an alternative solution, nanoparticles (NPs) of noble metals have been explored in amperometric biosensor development.…”