Nonenzymatic glucose sensor based on over-oxidized polypyrrole modified Pd/Si microchannel plate electrode

A nonenzymatic electrochemical glucose sensor based on mesoporous Au/Pt nanodendrites

Herein, an ultrasensitive and reliable nonenzymatic electrochemical glucose sensor has been developed, which is based on mesoporous Au/Pt nanodendrites prepared by a facile route aided by ultrasonication under mild conditions.

Non-enzymatic Glucose Sensor Based on Palladium Coated Nanoporous Gold Film Electrode

The non-enzymatic voltammetric and amperometric detection of glucose using a palladium coated nanoporous gold film electrode is described. The effect of surfactant on the fabrication of nanoporous gold film was also investigated. The voltammetric detection of glucose was performed by cyclic voltammetry. The sensor had good electrocatalytic activity towards oxidation of glucose, exhibited a rapid response (~6 s), and gave a linear range from 1 to 33 mM with a detection limit of 5 μM (with a signal to noise ratio of 3). The wide dynamic range, long-term stability, high sensitivity and selectivity, good reproducibility, and high resistance towards electrode fouling resulted in an ideal inexpensive amperometric glucose biosensor applicable for complex matrices.

Amperometric glucose biosensor based on electroconductive hydrogels

Fabrication of an enzyme amperometric biosensor for glucose via electropolymerization of pyrrole in the presence of glucose oxidase onto a hydrogel coated platinum electrode is hereby established as a viable biotransducer fabrication method. Platinum micro- (φ=25 μm) and macro- (φ=100 μm) electrodes were electrochemically activated and chemically modified with 3-aminopropyl-trimethoxysilane (APTMS), functionalized with acryloyl(polyethyleneglycol)-N-hydroxysuccinamide (ACRL-PEG-NHS), dipped into a polyHEMA based hydrogel cocktail and UV cross-linked. Electropolymerization of Py in the presence of GOx produced glucose responsive biotransducers that showed; (i) a 4-fold reduction in sensitivity compared with directly electropolymerized PPy films, (ii) an electropolymerization charge density dependence of biotransducer sensitivity and enzyme activity that was maximal at 1.0 mC/cm(2) with an apparent K(M) of 33 mM, (iii) interference screening of ascorbic acid and (iv) a temporal increase in sensitivity with storage over a 17 days period. This method has the ability to precisely and quantitatively add enzyme catalytic bioactivity to metal or semiconductor biointerfaces for applications in biosensors, bioelectronics and bionics.

Micellar nanoreactors for hematin catalyzed synthesis of electrically conducting polypyrrole

Enzymatic synthesis of doped polypyrrole (PPy) complexes using oxidoreductases (specifically peroxidases) is very well established "green" methods for producing conducting polypyrrole. The importance of this approach is realized by the numerous potential opportunities of using PPy in biological applications. However, due to very high costs and low acid stability of these enzymes, there is need for more robust alternate biomimetic catalysts. Hematin, a hydroxyferriprotoporphyrin, has a similar iron catalytic active center like the peroxidases and has previously shown to catalyze polymerization of phenol monomers at pH 12. The insolubility of hematin due to extensive self-aggregation at low pH conditions has prevented its use in the synthesis of conjugated polymers. In this study, we have demonstrated the use of a micellar environment with sodium dodecylbenzenesulfonate (DBSA) for biomimetic synthesis of PPy. The micellar environment helps solubilize hematin, generating nanometer size reactors for the polymerization of pyrrole. The resulting PPy is characterized using UV-visible, Fourier transform infrared, and X-ray photoelectron spectroscopy and reveals the formation of an ordered PPy/DBSA complex with conductivities approaching 0.1 S/cm.

Direct synthesis of metal oxide incorporated mesoporous SBA-15, and their applications in non-enzymatic sensing of glucose

One-step direct synthetic route is reported for the preparation of M-SBA-15 materials (M=Cu, Ni, Co, Fe, and Mn) with nSi/nM ratios ranging from 100 to 10 under mild acidic condition than conventionally employed for the synthesis of Si-SBA-15. Materials were characterized by a complementary combination of X-ray diffraction, nitrogen sorption, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared, and UV-visible spectroscopy. Experimental evidences show that metal oxides are incorporated in the pore wall of SBA-15 matrices. A non-enzymatic electrochemical sensor device was fabricated for glucose detection based on M-SBA-15 materials. Cyclic voltammetry and linear sweep voltammetry were used to evaluate the catalytic activity of the M-SBA-15 modified electrode toward glucose. It was found that the Cu-SBA-15 (Si/Cu=20) modified electrode showed enhanced electrocatalytic activity toward the oxidation of glucose in alkaline solution compared to that of the conventional CuO and other M-SBA-15 materials investigated in this study. Under the optimal detection conditions, the Cu-SBA-15 (Si/Cu=20) exhibited linear behavior in the concentration range from 10 μM to 20 mM for the quantification of glucose with a limit of detection of 10 μM. Moreover, the Cu-SBA-15 modified electrode was also relatively insensitive to commonly interfering species such as ascorbic acid, uric acid, and dopamine.